Re:Cost of media vs. "cost" of piracy
on
CD Copy Stopper
·
· Score: 1
What I've failed to understand throughout this whole ordeal, is the reasoning that affords people a special right to another's property without due compensation.
As I understand it, people reason that no one is being hurt. When one copies an author's work, the author doesn't lose anything except a potential sale that (as the argument goes) wouldn't have been realized anyhow.
Another popular line of reasoning is that the effect of one individual choosing to copy or not copy would make no appreciable difference in the end, and there's greater personal benefit to copying. Seems pretty straightfoward.
A third and more vexing line of reasoning is that the copier is actually helping the author by increasing awareness of the author's work, and potentially generating more sales for the author's work.
There are as many different reasons as there are copiers. You could certainly argue against any of the reasons, but to say that you don't understand the reasoning would be a serious insult to your intellect.
Regarding self-sacrifice vs. increasingly restricted freedom:
Individual self-sacrifice now will not likely abate increasingly restricted freedoms later.
An avid copier might ask: What is the benefit to me, if I stop copying? Others will continue copying and the increasingly restricted freedoms will happen anyhow. Meanwhile, I'll have missed out on all this value, just to have the Moral High Ground.
That sounds like a hard sell. How would you sell it?
(As usual, I've probably commented too late in the discussion for this to ever be seen. Sigh.)
11g is really 11a-style OFDM at 2.4 Ghz rather than the 5 Ghz band. There would be two (at least) 11g modes: a compatibility mode whereby OFDM packets and legacy 11b CCK packets coexist, and one which is "pure" OFDM at 2.4 Ghz.
The compatibility mode adds a huge overhead to each transmitted packet. An 11g transmitter in this mode must first complete a legacy 11b RTS/CTS operation on the air which, if successful, is followed by the actual packet. Even if the actual packet were transmitted at nearly infinite bandwidth, the effective bandwidth you'd see on a connection would be quite low - think 10 Mb/s on average. That's not exactly chopped liver and its way better than legacy 11b, but it's definitely not 54 Mb/s.
There are suprisingly large differences between 11a products, even those using the exact same vlsi chips. There are two primary reasons: differences in choice of output power amplifier (or lack thereof) and differences in choice of antenna. You can deduce some of what's going on by looking at power and sensitivity ratings in manufacturers product specs. By the way, this also a great way to distinguish between 11b products as well.
Second generation 11a products have much better receiver sensitivity and output power than the first generation versions. And they do transmit through walls... although not concrete or metal or mirrors or some ceramics.
The main reason why 11b can reach farther than 11a in some situations is that 11b can ratchet down to 1 Mb/s whereas 11a is defined for rates from 54 down to 6 Mb/s (11g is identical to 11a in this regard). The difference in SNR and sensitivity needed at a receiver to pick out the 11a or 11g signal accounts for nearly all of the differences in range... and these differences are quite small if you have a good 11a radio with a good antenna.
Thus, 11g will have the same power, SNR, and receiver sensitivity challenges as 11a in the 5 Ghz band, but will also have a small boost in signal propagation efficiency in the lower band. Don't get bamboozled by the hype about compatibility with 11b. Compatibility for sharing the channel does not imply that the radio properties of 11g are the same as 11b.
Most vendors are busy bringing out 11a+b base stations and NIC cards. 11g in compatibility mode looks like a nightmare, whereas 11g in "pure" mode looks like 3 more channels of high performance OFDM if you have an 11a radio that can tune to both the 5Ghz and 2.4 Ghz bands. Aside from the higher-power outdoor channels at 5.8, this provides 11 channels for OFDM (8 at 5 Ghz plus 3). And this means that a group of base stations in an AP-dense environment will certainly be able to find a clear channel.
I didn't say much about the PBCC-based 22 Mb/s products. PBCC is actually a clever design but is likely going to be overshadowed by OFDM at 5 Ghz (11a) and OFDM at 2.4 Ghz (11g variants).
As long I understand the answer IN CONTEXT to the problem, i.e. understanding the systemic thought processes involved, I've learned what I need to learn.
I thought this once. I'd go to calculus classes, go through the material and understand it with no difficulty. However, since I never actually practiced it, the knowledge would not stick, and I sank fast when exam time came.
This is the reason that collaboration is potentially bad when learning. If someone else gives you the solution, you may well understand the solution and the problem but you won't have the knowledge and experience to solve the problem yourself.
Moral of the story: Do your own homework, and do it all!
(Of course, if you're stuck, ask the teacher. They'll help you find the answer yourself instead of just giving it to you.)
Everquest reminds me of a study in which a pigeon is rewarded for pecking a button X times. As the researchers doubled and tripled X, the pigeon would keep on pecking the button, until the bird was pecking a huge number of times for each reward. The behaviour acquired with strong positive feedback persisted even after the feedback was gone.
Compare this to VLT gambling - press a button, maybe win a prize. If you don't win this time, perhaps the next big strike is a button push away, and you just can't afford to miss that chance.
Everquest has this kinds of feedback system.
Trade skills - drag a few items into the kiln (or whatever), click the combine button, receive the reward. There's the static feedback of the item itself, and the diminishing feedback and false sense of accomplishment from your trade skill increasing. As your trade skill goes up, you need to make more elaborate and costly items to keep it increasing. Who knows? Maybe the next item you make will bump your level again.
Levelling - It's easy at first to gain levels, and the rewards are great. You can get new spells, wear better weapons and armor, and kill monsters that were once fearsome. Any Everquest player knows the thrill of the "ding!" at each level. As you increase in level, the "ding!" becomes less frequent, and the rewards are not as dramatic, but the players still slog through 8 hours of play to get that bell.
The player is immersed in an online social group of people who do the same thing, and encourage each other to play longer. It feels like you're letting down your friends when you leave, and that your friends are depending on you to come back soon.
I played for about a month, in progressively longer and longer sessions. It's fortunate that I didn't have any obligations, being unemployed at the time, but the desire to play outweighed the necessity of finding work. It's only because I've been sucked in by this kind of compulsion before that I recognized it, and I deleted my character and never played again.
Some people can play the game for a couple hours a week and be happy with that. Some people can sit down at a VLT and play a few rounds for fun. Many people cannot, though, and many areas are banning VLTs because of the damage it causes to these people.
If all of that content could be picked up from some more local resource rather than having to go to a central server, you'd solve a lot of problems (system bandwidth, hosting costs, etc).
Such a system already exists. Many ISPs already use what's called a caching proxy to improve the experience for their customers, reduce bandwidth usage, and indirectly reduce the load on internet web sites. No P2P buzzword-compliant software required.
Already there's a few problems:
Some people won't use the proxy because of privacy concerns (my private data, stored in a cache somewhere on the internet I don't control?!?
Some people won't use the proxy because they feel it's slow and unreliable. It's an extra step between your end and the other end, and it's going to introduce latency. Certainly no worse than the most ideal P2P setup, though.
Some sites contain content that can't be cached, like live video feeds. Sites with content generated dynamically (like Slashdot) aren't very cache-friendly either. Like most P2P implementations, caching proxies work best with popular, static content.
We have a system that would offer all the benefits you remarked on (system bandwidth, hosting costs), and still can't stave off the dreaded slashdot effect. Granted, caching proxies are hardly ubiquitous, but P2P networks suitable for this are nigh nonexistant.
I think the government should regulate everything from Cell phones to Computers. Make it so everytime you go buy electronics, you must show your ID in order to purchase it; then interrogate the person if they don't have their card on them.
"Those who express random thoughts to legislative committees are often surprised and appalled to find themselves the instigators of law." -- Mark B. Cohen
Think about how many people [use] the internet [..] these people are literally terrorized when they get a virus or worm [..]
A friend of mine is terrified by spiders, though the spiders aren't trying to scare her. I feel that terrorism depends on intent, not effect.
I expect that viruses are more often released with the intent to scribble "Kilroy was here" on a thousand walls than to cause fear or terror in computer users.
There are virus writers, and there are cyberterrorists, but a virus writer is not always a cyberterrorist even if some people fear viruses.
You should not be using insecure products, but that does not excuse the crime.
Read the original author's post more carefully. He wasn't justifying the crime because of poor security, but suggesting that once one identifies a product with poor security, one should use something else.
Fool me once, shame on you. Fool me twice, shame on me.
Of course, this doesn't even touch on the poster's main point, that one cannot liken a virus writer to a terrorist as his intent is different and the scope of his damage is far less tangible.
[..] the fewer chips, the easier a system is to write an emulator for!
This seems like an oversimplification. If the chips integrate the functions of several normally seperate chips, as these surely do, emulation isn't any easier. It may even be harder, in fact, since you can't build on chip emulations that may already be available. With custom ICs like these, getting specs may be more difficult too.
However, the lack of package management holds it back
This is a common misconception. pkgtool makes it very easy to add, update, and remove packages, and the simple package format makes it easy to make your own. In combination with installwatch and install2slack, maintaining multiple machines is a no-brainer.
If you want pre-built packages for slackware, you might try linuxmafia, where you can find contributed packages for a wide variety of software.
Now, if you mean that slackware's package management system doesn't check dependancies, you'd be right. It's not as if it doesn't exist, though.
Why not let the 2 VM's compete and the users will decide?
The problem is the duplication of effort and decreased manpower for each VM. Not only that, but any project that works closely with the VM has to test under twice as many conditions, and may require different code for each. Talk about a maintenance problem.
It's certainly good to have competition to bring out the best in each system, but it would be horribly inefficient to keep it going in the long run.
Regarding the users choosing - the users don't have the opportunity to choose only on the basis of the VM. It's not like they can apply the "VM patch" to the stock kernel to try out the other one, rather, they have to apply a fairly large -ac patch that changes a lot of unrelated things.
Okay, I'll bite. Where does one get an x.509 certificate, and how much do they cost? I'm sure you can make your own self-signed certificate, but is it reasonable to trust such a certificate when presented?
Then, start pushing content servers to support opportunistic encryption [...]
One problem with IPSec opportunistic encryption is that it requires both ends to have their public key available associated with the reverse dns records. Few consumers have control over their reverse dns records at this point.
Not only that, but the whole DNSSEC infrastructure isn't really in place yet for this kind of thing to be widely deployed. How do you know you're getting the key from the right place? (OTOH, DNS spoofing and poisoning are active attacks, vs. passive sniffing.)
In addition, using encryption would add a huge overhead, especially for large sites. I think you'd have a hard time convincing content providers to support it unless there was some clear advantage to them in doing so.
Opportunistic encryption is a great idea, but it clearly isn't cure-all that some make it out to be.
From the article it would seem that until patches are available for your kernel, you can remove the suid (chmod -s) from the newgrp binary.
It's actually a kernel bug, and I'm told that any suid binary can be a vector. The temporary fix is to chmod -s all suid binaries on the system until it can be properly fixed.
We've always used IBM drives in our shop, and we've rarely had any incident with them. But one day we needed a drive for a system and all the IBMs were out of stock at our supplier.
Now, we've had bad luck with Maxtors before, but we figured that we'd give it a chance, as they may have improved since last time we tried them.
Now, not even two months later, the drive has to be sent in for RMA. I think we'll be sticking with IBMs for the time being.
We never did get around to stocking the IBM 75GXP referenced, though. Lucky, I guess.
[..] otherwise we'll still be burning dead dinosaurs to make the hydrogen.
This isn't as bad as it sounds. Power plants can operate at much higher temperatures than automobile engines, and can therefore achieve much better efficiency. Not only that, but the combustion is more complete, and much more elaborate pollution-control measures can be used.
In short, if you make a power plant that would produced energy to drive a thousand cars, it would burn less fuel than those thousand cars would burn individually.
BUT I see no harm in downloading a few songs to try out a new cd before I go spend $20 for my own copy. I HATE buying a cd for a one-hit-wonder band, sampling the music beforehand is a way to prevent that.
Most music vendors allow you to listen to a CD in store before you buy it. This isn't a very good excuse.
What if I was to create a file consisting of nothing but the letter X that was, say, 1Gb in size, and leave it on my linux webserver with a name like "root.exe"? It wouldn't take all that many requests for the attacking system to run out of HD space. Granted service on my server might suck for a bit, but eventually if enough linux admins did this the target systems would simply shutdown for lack of swap space or HD space or whathaveyou.
What makes you think that the worm would save the file it download? Granted, it might make some room temporarily for it, but it certainly doesn't store the file. Meanwhile, you've got 10 or more worms slurping the file, consuming your bandwidth. This is even worse than if you had done absolutely nothing at all!
If you really want to waste your time with this, the easiest thing to do is to drop the initial syn, so that the worm has to wait for a tcp timeout. If you want something more elaborate, try the Labrae (sp?) thing that everyone's talking about. It requires one or more unused addresses to work, though. If you're actually running a webserver, none of these options will work and you're better off just ignoring it.
[...] allowed only to check against existing wanted criuminals and terrorists and not allowed to track the movements of those not in the database or to store long-term information on non-tagged individuals [...]
Sounds great! But what if you're in the database and you don't know it, perhaps because of some minor clerical error?
Re:IRC can be fixed easily.
on
Secure IRC?
·
· Score: 1
No change in protocol required. With the existing protocol, if A wants to dcc to B, it sends a ctcp dcc chat through the server containing an ip and a port to connect to. If B accepts, B's client connects to the ip and port that A provided. If B doesn't accept, no packet is sent and no address is revealed.
All you have to do is remember to turn DCC autoget off.
Not so long ago, kiddies commonly bounced through misconfigured proxies onto irc in order to hide their true hostname, avoid accountability, etc.
Most proxies do not provide ident service. Therefore, the easiest way to block these people was to block non-ident clients.
The other alternative is to scan hosts as they come in for open proxies, but you can imagine the floods of "your server portscanned me" emails. It's also yet another extra program to be running on the server, with all the bugs inherent in that.
This is a pain for people legitimately using proxies, but for the rest of us it's a minor nuisance and a major win.
A customer had this problem fairly recently. He'd sit down in his big fabric-covered office chair (generating a terrific static charge), and put his Palm in the cradle. After a couple of rounds of this, the motherboard was okay, but the onboard serial port was dead.
Slashdot Mirror
As I understand it, people reason that no one is being hurt. When one copies an author's work, the author doesn't lose anything except a potential sale that (as the argument goes) wouldn't have been realized anyhow.
Another popular line of reasoning is that the effect of one individual choosing to copy or not copy would make no appreciable difference in the end, and there's greater personal benefit to copying. Seems pretty straightfoward.
A third and more vexing line of reasoning is that the copier is actually helping the author by increasing awareness of the author's work, and potentially generating more sales for the author's work.
There are as many different reasons as there are copiers. You could certainly argue against any of the reasons, but to say that you don't understand the reasoning would be a serious insult to your intellect.
Regarding self-sacrifice vs. increasingly restricted freedom:
An avid copier might ask: What is the benefit to me, if I stop copying? Others will continue copying and the increasingly restricted freedoms will happen anyhow. Meanwhile, I'll have missed out on all this value, just to have the Moral High Ground.
That sounds like a hard sell. How would you sell it?
(As usual, I've probably commented too late in the discussion for this to ever be seen. Sigh.)
Probably a clever advertisement for a new movie about time travel and paradoxes and all that goodness.
Of course, it couldn't hurt to email the addresses and ask (with a throwaway account, of course - damn spammers.)
11g is really 11a-style OFDM at 2.4 Ghz rather than the 5 Ghz band. There would be two (at least) 11g modes: a compatibility mode whereby OFDM packets and legacy 11b CCK packets coexist, and one which is "pure" OFDM at 2.4 Ghz.
... and these differences are quite small if you have a good 11a radio with a good antenna.
The compatibility mode adds a huge overhead to each transmitted packet. An 11g transmitter in this mode must first complete a legacy 11b RTS/CTS operation on the air which, if successful, is followed by the actual packet. Even if the actual packet were transmitted at nearly infinite bandwidth, the effective bandwidth you'd see on a connection would be quite low - think 10 Mb/s on average. That's not exactly chopped liver and its way better than legacy 11b, but it's definitely not 54 Mb/s.
There are suprisingly large differences between 11a products, even those using the exact same vlsi chips. There are two primary reasons: differences in choice of output power amplifier (or lack thereof) and differences in choice of antenna. You can deduce some of what's going on by looking at power and sensitivity ratings in manufacturers product specs. By the way, this also a great way to distinguish between 11b products as well.
Second generation 11a products have much better receiver sensitivity and output power than the first generation versions. And they do transmit through walls... although not concrete or metal or mirrors or some ceramics.
The main reason why 11b can reach farther than 11a in some situations is that 11b can ratchet down to 1 Mb/s whereas 11a is defined for rates from 54 down to 6 Mb/s (11g is identical to 11a in this regard). The difference in SNR and sensitivity needed at a receiver to pick out the 11a or 11g signal accounts for nearly all of the differences in range
Thus, 11g will have the same power, SNR, and receiver sensitivity challenges as 11a in the 5 Ghz band, but will also have a small boost in signal propagation efficiency in the lower band.
Don't get bamboozled by the hype about compatibility with 11b. Compatibility for sharing the channel does not imply that the radio properties of 11g are the same as 11b.
Most vendors are busy bringing out 11a+b base stations and NIC cards. 11g in compatibility mode looks like a nightmare, whereas 11g in "pure" mode looks like 3 more channels of high performance OFDM if you have an 11a radio that can tune to both the 5Ghz and 2.4 Ghz bands. Aside from the higher-power outdoor channels at 5.8, this provides 11 channels for OFDM (8 at 5 Ghz plus 3). And this means that a group of base stations in an AP-dense environment will certainly be able to find a clear channel.
I didn't say much about the PBCC-based 22 Mb/s products. PBCC is actually a clever design but is likely going to be overshadowed by OFDM at 5 Ghz (11a) and OFDM at 2.4 Ghz (11g variants).
Cite examples.
I thought this once. I'd go to calculus classes, go through the material and understand it with no difficulty. However, since I never actually practiced it, the knowledge would not stick, and I sank fast when exam time came.
This is the reason that collaboration is potentially bad when learning. If someone else gives you the solution, you may well understand the solution and the problem but you won't have the knowledge and experience to solve the problem yourself.
Moral of the story: Do your own homework, and do it all!
(Of course, if you're stuck, ask the teacher. They'll help you find the answer yourself instead of just giving it to you.)
Everquest reminds me of a study in which a pigeon is rewarded for pecking a button X times. As the researchers doubled and tripled X, the pigeon would keep on pecking the button, until the bird was pecking a huge number of times for each reward. The behaviour acquired with strong positive feedback persisted even after the feedback was gone.
Compare this to VLT gambling - press a button, maybe win a prize. If you don't win this time, perhaps the next big strike is a button push away, and you just can't afford to miss that chance.
Everquest has this kinds of feedback system.
The player is immersed in an online social group of people who do the same thing, and encourage each other to play longer. It feels like you're letting down your friends when you leave, and that your friends are depending on you to come back soon.
I played for about a month, in progressively longer and longer sessions. It's fortunate that I didn't have any obligations, being unemployed at the time, but the desire to play outweighed the necessity of finding work. It's only because I've been sucked in by this kind of compulsion before that I recognized it, and I deleted my character and never played again.
Some people can play the game for a couple hours a week and be happy with that. Some people can sit down at a VLT and play a few rounds for fun. Many people cannot, though, and many areas are banning VLTs because of the damage it causes to these people.
Such a system already exists. Many ISPs already use what's called a caching proxy to improve the experience for their customers, reduce bandwidth usage, and indirectly reduce the load on internet web sites. No P2P buzzword-compliant software required.
Already there's a few problems:
We have a system that would offer all the benefits you remarked on (system bandwidth, hosting costs), and still can't stave off the dreaded slashdot effect. Granted, caching proxies are hardly ubiquitous, but P2P networks suitable for this are nigh nonexistant.
"Those who express random thoughts to legislative committees are often surprised and appalled to find themselves the instigators of law." -- Mark B. Cohen
A friend of mine is terrified by spiders, though the spiders aren't trying to scare her. I feel that terrorism depends on intent, not effect.
I expect that viruses are more often released with the intent to scribble "Kilroy was here" on a thousand walls than to cause fear or terror in computer users.
There are virus writers, and there are cyberterrorists, but a virus writer is not always a cyberterrorist even if some people fear viruses.
Read the original author's post more carefully. He wasn't justifying the crime because of poor security, but suggesting that once one identifies a product with poor security, one should use something else.
Fool me once, shame on you. Fool me twice, shame on me.
Of course, this doesn't even touch on the poster's main point, that one cannot liken a virus writer to a terrorist as his intent is different and the scope of his damage is far less tangible.
When did summer come to Winnipeg last year, you ask? Well, if memory serves, I think it was a Tuesday.
-- shamelessly misappropriated from the fortune file
This seems like an oversimplification. If the chips integrate the functions of several normally seperate chips, as these surely do, emulation isn't any easier. It may even be harder, in fact, since you can't build on chip emulations that may already be available. With custom ICs like these, getting specs may be more difficult too.
This is a common misconception. pkgtool makes it very easy to add, update, and remove packages, and the simple package format makes it easy to make your own. In combination with installwatch and install2slack, maintaining multiple machines is a no-brainer.
If you want pre-built packages for slackware, you might try linuxmafia, where you can find contributed packages for a wide variety of software.
Now, if you mean that slackware's package management system doesn't check dependancies, you'd be right. It's not as if it doesn't exist, though.
The problem is the duplication of effort and decreased manpower for each VM. Not only that, but any project that works closely with the VM has to test under twice as many conditions, and may require different code for each. Talk about a maintenance problem.
It's certainly good to have competition to bring out the best in each system, but it would be horribly inefficient to keep it going in the long run.
Regarding the users choosing - the users don't have the opportunity to choose only on the basis of the VM. It's not like they can apply the "VM patch" to the stock kernel to try out the other one, rather, they have to apply a fairly large -ac patch that changes a lot of unrelated things.
Okay, I'll bite. Where does one get an x.509 certificate, and how much do they cost? I'm sure you can make your own self-signed certificate, but is it reasonable to trust such a certificate when presented?
One problem with IPSec opportunistic encryption is that it requires both ends to have their public key available associated with the reverse dns records. Few consumers have control over their reverse dns records at this point.
Not only that, but the whole DNSSEC infrastructure isn't really in place yet for this kind of thing to be widely deployed. How do you know you're getting the key from the right place? (OTOH, DNS spoofing and poisoning are active attacks, vs. passive sniffing.)
In addition, using encryption would add a huge overhead, especially for large sites. I think you'd have a hard time convincing content providers to support it unless there was some clear advantage to them in doing so.
Opportunistic encryption is a great idea, but it clearly isn't cure-all that some make it out to be.
It's actually a kernel bug, and I'm told that any suid binary can be a vector. The temporary fix is to chmod -s all suid binaries on the system until it can be properly fixed.
We've always used IBM drives in our shop, and we've rarely had any incident with them. But one day we needed a drive for a system and all the IBMs were out of stock at our supplier.
Now, we've had bad luck with Maxtors before, but we figured that we'd give it a chance, as they may have improved since last time we tried them.
Now, not even two months later, the drive has to be sent in for RMA. I think we'll be sticking with IBMs for the time being.
We never did get around to stocking the IBM 75GXP referenced, though. Lucky, I guess.
[..] otherwise we'll still be burning dead dinosaurs to make the hydrogen.
This isn't as bad as it sounds. Power plants can operate at much higher temperatures than automobile engines, and can therefore achieve much better efficiency. Not only that, but the combustion is more complete, and much more elaborate pollution-control measures can be used.
In short, if you make a power plant that would produced energy to drive a thousand cars, it would burn less fuel than those thousand cars would burn individually.
BUT I see no harm in downloading a few songs to try out a new cd before I go spend $20 for my own copy. I HATE buying a cd for a one-hit-wonder band, sampling the music beforehand is a way to prevent that.
Most music vendors allow you to listen to a CD in store before you buy it. This isn't a very good excuse.
What if I was to create a file consisting of nothing but the letter X that was, say, 1Gb in size, and leave it on my linux webserver with a name like "root.exe"? It wouldn't take all that many requests for the attacking system to run out of HD space. Granted service on my server might suck for a bit, but eventually if enough linux admins did this the target systems would simply shutdown for lack of swap space or HD space or whathaveyou.
What makes you think that the worm would save the file it download? Granted, it might make some room temporarily for it, but it certainly doesn't store the file. Meanwhile, you've got 10 or more worms slurping the file, consuming your bandwidth. This is even worse than if you had done absolutely nothing at all!
If you really want to waste your time with this, the easiest thing to do is to drop the initial syn, so that the worm has to wait for a tcp timeout. If you want something more elaborate, try the Labrae (sp?) thing that everyone's talking about. It requires one or more unused addresses to work, though. If you're actually running a webserver, none of these options will work and you're better off just ignoring it.
[...] allowed only to check against existing wanted criuminals and terrorists and not allowed to track the movements of those not in the database or to store long-term information on non-tagged individuals [...]
Sounds great! But what if you're in the database and you don't know it, perhaps because of some minor clerical error?
No change in protocol required. With the existing protocol, if A wants to dcc to B, it sends a ctcp dcc chat through the server containing an ip and a port to connect to. If B accepts, B's client connects to the ip and port that A provided. If B doesn't accept, no packet is sent and no address is revealed.
All you have to do is remember to turn DCC autoget off.
Not so long ago, kiddies commonly bounced through misconfigured proxies onto irc in order to hide their true hostname, avoid accountability, etc.
Most proxies do not provide ident service. Therefore, the easiest way to block these people was to block non-ident clients.
The other alternative is to scan hosts as they come in for open proxies, but you can imagine the floods of "your server portscanned me" emails. It's also yet another extra program to be running on the server, with all the bugs inherent in that.
This is a pain for people legitimately using proxies, but for the rest of us it's a minor nuisance and a major win.
A customer had this problem fairly recently. He'd sit down in his big fabric-covered office chair (generating a terrific static charge), and put his Palm in the cradle. After a couple of rounds of this, the motherboard was okay, but the onboard serial port was dead.