until recently, the service was
provided for free for civilian purposes with a low precision (I think it was 5 meters, or something like that).
It still is free for civilian use - the L1 signal without SA (Selective Availablity - a deliberate coarsening of the accuracy that can be obtained - this was turned off by the Clinton administration) is good for about 15m. The military gets to use the L1 signal as well as L2, which allows them to correct for ionospheric delays (which are variable) and they get meter accuracies. Crypto keys are required to use the L2 signal.
but they could decided to... stop civilian service
altogether.
Not bloody likely! The FAA has been decommissioning (not repairing) lots of terrestrial navigation systems (like VORs and NDBs) based on "everyone has GPS". Additionally, with the deployment of WAAS - Wide-Area Augmentation System, a network of ground stations that calculates errors for each satellite and uses a geostationary satellite to send these corrections to aircraft in real-time - US civil aviation becomes even more dependent on GPS. They can turn GPS off only by [effectively] grounding the airlines.
(GPS+WAAS is good enough for accuracy in inches, even if they turn SA back on. WAAS will only work in the US though.)
Alpha's are like 1960's muscle cars. They're fast, but only because
of the brute force under the hood. X86 machines are sleek and smoothe like a Porche because they use
brilliant engineering and specialised extensions like SSE.
Surely you jest?
Alphas are the Porsches. The x86 architecture is a horribly ugly mass of cancerous protrusions and cruft that still has to perform like an 8080. All those extended instructions like MMX etc. are done better by the Alpha.
-atrowe: Card-carrying Mensa member. I have no toleranse for stupidity.
Sendmail and bind can not be patched in such a way as to eventually become completely secure.
Are you actually going to back up these assertions with facts, or just look like a blowhard?
You might start with the versions of these programs that that OpenBSD team has gone through. What bugs or weaknesses exist in them? (Let's stick to weaknesses that are not inherent to email or DNS, i.e. weaknesses that qmail and djbdns have fixed for you.)
I wouldn't not recommend anything by DJB, but let's not carried away with invective.
The headline for the article screams "Terror groups hide behind Web encryption." But the best they can do in the body is "Hidden in the
X-rated pictures on several
pornographic Web sites and the posted
comments on sports chat rooms may
lie the encrypted blueprints of the next
terrorist attack against the United
States or its allies."
This is followed by a bunch of outrageous speculation, all attributed to "U.S. and foreign officials", "U.S. officials", and the mysterious "officials".
What the fuck has happened to reporters and journalism?
"What is the harm or crime in a man jacking off to computer generated photos of six year olds?"
And to that, I say this : If you actually need an answer to that question, you are yourself in dire need of help.
This sounds to me like the ravings of a fanatic who can't justify his position rationally, therefore he attacks the person instead of the argument. Note to "javabandit": we people who have a grasp of dialectic and/or reality would use big words from a dead language to describe this: ad hominem.
The above paragraph was also a form of ad hominem argument on my part; it's just phrased much more eloquently; with finesse. If you must resort to "crooked reasoning", at least learn to do it well.
So: yes, I actually need an answer to that question. I don't see the harm in a man or a woman masturbating to computer generated images of children, cats, or giant saguaros. And yes, I am in need of help - how did you know? I could use some financial help; I could use good investment advice; and I certainly could use some help in taking care of household chores.
The question in the title: Q: What's a fanatic? A: Someone who knows what God would do if he only had all the facts.
The legislators and the "Moral Majority" idiots want to convince you that it's about porn, because everyone believes porn is bad, right?
No; it's about adult content. People think that certain extreme political viewpoints are not suitable for children. Or the information that contraception and abortion are both legal in the US - Planned Parenthood. Or any sex-oriented words even if the context is non-sexual - i.e. the pseudo-crimes of profanity, obscenity etc. This just fucking ridiculous! There. Slashdot has (and always has had) "adult content".
There are actually cretins, morons and imbeciles who believe that the views of organisations like the ACLU and Amnesty International are "adult content" and they don't want their kids exposed to it until they've completed their brainwashing sessions. If these morons can't control their own children they certainly shouldn't be allowed to control the whole nation.
Q. Will instituting some sort of access trail or ID verification for non-mainstream political web sites restrict their free speech rights? Will this kind of legislation harm minors because they were not allowed to get information about contraception without proof of ID? A. You bet your ass it will.
It's not like IIS has the same usage numbers among web servers as MS-Windows has on the desktop...
They're targeted because they're the most vulnerable target. That's all.
Re:And here comes Carnivore...
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The war ended, and civil liberties came back.
You see, despite what Baby Bush (or Spurious George or whatever you want to call that XXXX) says, this is not a war.
There is no identified enemy; and there is nothing that will define a point where it's over. If we will never know when the war ends, when do our civil liberties come back?
The things that we can do are: implement the security procedures we already have. Airport security is a joke - manned by minimum-wage workers who are thinking about how long it is till their shift ends. I can't count the number of times that I have set off the metal detector because I was wearing hiking boots with a metal shank and eyelets. Did they make me take off my boots and see what it was that set it off? No. I said "it's my boots" and they waved me through.
And if you make a connecting flight on a twin-turboprop commuter, take a guess how much the first officer makes. $15,000 a year. There is no way we can really improve security until we are willing to pay the people in charge of it what our security is worth.
But the thing is that the goddamn fucking people will squawk like hell if airline tickets go up by 10% but won't mind strip searches before every flight. Morons.
Re:And here comes Carnivore...
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Compare this kind of security to computer security... Would you put a naked Win 95 box on the net with no
protection?
I am so tempted to call you an idiot. But I won't.
The better analogy is: you're using secure OSs and firewalls; would you give the various police forces an account, and the root password, on all your systems? That way they can make sure that nothing bad happens to your computers.
I would rather be inconvenienced and safe next time I am on a
plane, instead of complaining about loss of civil liberties.
You want to be safe, stay in bed. Feel free to volunteer for body cavity searches the next time you get on an airplane. The rest of us would like to lead lives of sanity and proportion.
Sorry for the provocative tone of this message. However, nothing has changed about the security, or lack thereof, in our lives over the last few days. You didn't really think that something like this couldn't happen, did you? Or that the government was going to save you from something like this? So why a knee-jerk reaction for something that still won't keep an enormity like this happening again? Any two-bit terrorist could charter a business jet, load it full of fertilizer and fuel oil and fly that thing into DisneyWorld or Sears Tower or wherever the hell he wants. And there's nothing the government or anyone can do about it.
Instead, why don't we think about: what is it about our foreign policy that makes so many people around the world hate us so much?
On one flight in an airliner, the sun was abeam the aircraft, and on the left side; I had a window seat on the right side over the wing. I saw a shadow on the wing that looked a lot like Schlieren images of shocks I've seen [I used to volunteer at a wind-tunnel lab as an undergraduate]. I think this was on a B727, during cruise flight so it was not unreasonable that there be a weak shock on the upper surface. The shadow also moved as I expected a shock to move when small control movements were made.
Could that really have been a shock, or was I seeing some sort of condensation artifact? (I have seen the normal condensation effects - in wingtip vortices, flap boundaries, and even a cloud over a large part of the upper surface.)
Unfortunately I couldn't keep track of the shadow all the way to the first power reduction since it got overcast.
That's Part 91, which is what individual pilots fly under.
Not exactly; Part 135 and Part 121 operators also have to follow Part 91 (and Part 61).
As 91.1 of the Holy Scripture says:
91.1 Applicability.
(a) Except as provided in paragraphs (b) and (c) of this section and 91.701 and 91.703, this part prescribes
rules governing the operation of aircraft (other than moored balloons, kites, unmanned rockets, and unmanned
free balloons, which are governed by part 101 of this chapter, and ultralight vehicles operated in accordance with
part 103 of this chapter) within the United States, including the waters within 3 nautical miles of the U.S. coast.
(Paragraphs (b) and (c) deal with off-shore ops. and passengers, respectively; 91.701 and 91.703 are foreign ops.) And pilots for hire can fly Part 91 ops, as in corporate flight depts.
It's a heck of a lot easier to look at a needle and say, "oooh, that one's getting
close to the red part," than to look at an LCD and say, "73. what does 73 mean?
A poorly designed interface is just that. Analog instruments are better for quick scans and can display trends better; so a glass cockpit will give you an analog picture of the situation. They don't give you degrees of bank and roll numerically; they draw a picture of a horizon.
The cool thing though is: much more flexibility. Instead of a needle showing you deviations from your course, they can depict a "highway in the sky" on top of the artificial horizon. Instead of a horrendously expensive mechanical HSI (Horizontal Situation Indicator, a moving compass rose that has superimposed navigation needles) an electronic HSI can show you a compass rose with nav. moving map, and overlay weather radar, terrain, traffic and lightning strike data.
And those LCD glass cockpits are much more reliable than the good ol' steam gauges. Don't get me wrong, I don't feel that my life is being placed in jeopardy because the airplanes I fly have steam gauges; but man alive, I drool over what those colour displays can do. (The FAA is a lot more conservative now, and these systems are much more reliable, accurate and readable than mechanical instruments.)
GPS doesn't work at supersonic speeds anyway so there wouldn't be much point in having it.
GPS works fine at any speed. (Well, non-relativistic speeds, anyway...)
A few things to keep in mind:
Consumer GPS chipsets are limited to 900kt.
There's no reason a foreign government/company couldn't design a GPS chipset.
Concorde cruises around Mach 2 @ FL600
Above FL400, the speed of sound is 580 kt so 900 kt = Mach 1.5.
GLONASS [the Russian sat. nav. system] does not have speed limits.
But the most important thing is: inertial navigation works just fine - especially if there are <20 airplanes in the world flying at those speeds and altitudes!
X11 has "clear limitations"?
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Quicktime In Linux
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· Score: 2, Informative
Velex wrote:
... X has some clear limitations
Sounds like you've never used X11. What are these "clear limitations"?
In fact, X11 is still vastly superior to Win32 GDI (or whatever they're calling it today).
I work from home two days a week, and I have DSL. I use Unix/X11 for everything - which means that I can do anything I need to using any program on any machine (whether it's at home or at the office) from either home or the office. Working from home is identical to working at the office - except for the noise, the constant interruptions, meetings, etc.
That one feature by itself is enough to blow all the Micros**t crap out of the water. (Leaving aside the fact that X11 can do anything that can be done on Windows. You might say that "Program X on Windows does foobar, show me an X11 program that does that" but you will miss the point. The lack of existence of that program is not due to any weakness of X11; it's simply because no one has written that program yet.)
Nobody wants to compile his own software just to put it under his user's home directory instead of globally.
There needs to be something like InstallShield or Wise Install for Windows -- I double click the executable
on my desktop, answer a few simple questions, and, *poof*, my scripts are updated and the software is
installed.
You don't really think that a significant proportion of Linux/Unix users today compile things from source, do you? (A few do - gluttons for punishment like me... but I like having the source so if some bug really starts to annoy me, I can jump in and fix it.) Everyone else I know runs some sort of desktop; on Linux, K or Gnome. On both those systems, when you want to install something, you click on it, a window pops up that you type the root password into, and voila! it sets everything up, including billions of annoying icons everywhere, just like you want.
(If you really mean to argue for the Windows Way of "everyone is logged in as Administrator all the time" - well, I wish I hadn't typed all this stuff in, because there's no hope.)
Don't get me wrong: if Program X that you need is only available on Operating System Y, of course your machine should be running Y. We use programs, not operating systems. (Again, except for the aforementioned gluttons for punishment like me - I've been writing code on Unix for 20 years and I just can't use any other OS. And I do watch video on Linux - you just need a video card that XFree86 supports well. And yes, it's not likely that Mom will be able to figure all this out.)
But don't make airy claims about "X having clear limitations".
why is it that the encryption schemes in DeCSS, Adobe
PDF, and now 802.11 are so 'easily' broken, as opposed to 3DES or RSA that are being used in SSH &
SSL?
Because all these companies hire programmers to design cryptosystems. Designing crypto is harder than you think. (Think for a bit.) No, even harder than that. Basically if your name isn't Shamir, Rivest, Yao, Blum, Diffie, Goldwasser, etc. you shouldn't be designing crypto.
Knuth has an excellent section on how hard good crypto is to design, in Seminumerical Algorithms in the chapter on pseudo-random numbers etc.
why aren't these algorithms being applied in 802.11?
It always boils down to money and stupidity. To stupid to know how hard crypto is; too cheap to hire people who can do it right.
Another hint: their customers are paying them to transport packets. They can say "We will transport x packets per second for you." But why should they have any right to look inside the packets? Why should they be allowed to look at certain fields of certain packets of a certain protocol? Or, in a technical sense: they are paid to transport IP packets. Why should they be allowed to look at anything in the payload, like TCP or UDP headers? They paid for IP, not "TCP only, and only as long as inbound packets don't have the SYN bit set."
What would your reaction be if the post office starting telling you that you're not allowed to receive a letter from someone that you haven't already sent a letter to? Or, if you get an envelope, and inside it is another envelope, inside which is the letter, then that inside envelope can only be pink, but it better not have a floral border.
What
if your boss emails a word or access docuement to you on Saturday and demands to have it finished by
monday?
Quit.
(Are you getting paid overtime to work on the weekend?)
I just don't buy the attitude that my manager is my "boss" - if s/he makes unreasonable demands I let him/her know, and loudly. They can just as well distribute that document in HTML (hell, or even PDF) so everyone can read it.
But I just wouldn't take a job that required me to use Windows. They're paying me a shitload of money to be a Unix guy, and a Unix guy is what they're getting.
They could make it work if they wanted to. Heck, in Boulder, CO, they have sensors that work for
bicycles.
It's not optional for them; in every state of the US, bicycles are vehicles with all the rights and responsibilities of any other sort of vehicle. If you have a sensor that a bicycle doesn't trip, complain; they have to fix it.
Of course I'm sure that in some states (I won't name any names but just point to the southeastern part of the US) all vehicles - motor vehicles as well as bicycles - are equal, but some are more equal than others....
Yeah, you'd think they would make those things a bit more sensitive. I mean, do people who
weigh as much as a motorcycle go for a walk at 3 AM?
They are not weight sensitive: a scale that would work in all weather and survive re-paving would be too expensive. No, those are inductive sensors - a loop (or two) of wire, that when a piece of metal is on it, it trips.
By law, those things have to trip not just for motorcycles, but for bicycles as well. Those sensors have a part that is the most sensitive; in enlightened states (California and Arizona are where I've seen them) they paint a little picture of a bicycle on the road where the sensor is most sensitive.
If you have a sensor in your town that doesn't trip for your bike (motorcycle or bicycle) be sure to write a letter of complaint to your local municipal authority. To calibrate these things I suspect the technician just moves his Chrysler LeBehemoth on the sensor instead of doing it right.
So, the US military can at any time decide it's time to switch the GPS to low-accuracy
No, they cannot.
Civil aviation uses GPS - a lot - for navigation. It's not just a toy for bored geeks in cars.
It's true that airliners will never navigate solely on GPS; a complete shut-down of GPS will not [should not] lead to any airliners crashing into mountains. However, too many private pilots do rely solely on GPS.
While global loss of GPS will not lead any airliners to mountains, it will lead to massive saturation of the system. For example, on Oceanic routes (trans-Atlantic and trans-Pacific) having a GPS sensor allows you to meet a higher navigation performance rating which means you can use the preferred tracks.
Slashdot Mirror
(GPS+WAAS is good enough for accuracy in inches, even if they turn SA back on. WAAS will only work in the US though.)
'Nuff said.
(Or formal logic.)
Surely you jest?
Alphas are the Porsches. The x86 architecture is a horribly ugly mass of cancerous protrusions and cruft that still has to perform like an 8080. All those extended instructions like MMX etc. are done better by the Alpha.
Poor spelling is just fine though.You might start with the versions of these programs that that OpenBSD team has gone through. What bugs or weaknesses exist in them? (Let's stick to weaknesses that are not inherent to email or DNS, i.e. weaknesses that qmail and djbdns have fixed for you.)
I wouldn't not recommend anything by DJB, but let's not carried away with invective.
The headline for the article screams "Terror groups hide behind Web encryption." But the best they can do in the body is
"Hidden in the X-rated pictures on several pornographic Web sites and the posted comments on sports chat rooms may lie the encrypted blueprints of the next terrorist attack against the United States or its allies."
This is followed by a bunch of outrageous speculation, all attributed to "U.S. and foreign officials", "U.S. officials", and the mysterious "officials".
What the fuck has happened to reporters and journalism?
The above paragraph was also a form of ad hominem argument on my part; it's just phrased much more eloquently; with finesse. If you must resort to "crooked reasoning", at least learn to do it well.
So: yes, I actually need an answer to that question. I don't see the harm in a man or a woman masturbating to computer generated images of children, cats, or giant saguaros. And yes, I am in need of help - how did you know? I could use some financial help; I could use good investment advice; and I certainly could use some help in taking care of household chores.
The question in the title:
Q: What's a fanatic?
A: Someone who knows what God would do if he only had all the facts.
No; it's about adult content. People think that certain extreme political viewpoints are not suitable for children. Or the information that contraception and abortion are both legal in the US - Planned Parenthood. Or any sex-oriented words even if the context is non-sexual - i.e. the pseudo-crimes of profanity, obscenity etc. This just fucking ridiculous! There. Slashdot has (and always has had) "adult content".
There are actually cretins, morons and imbeciles who believe that the views of organisations like the ACLU and Amnesty International are "adult content" and they don't want their kids exposed to it until they've completed their brainwashing sessions. If these morons can't control their own children they certainly shouldn't be allowed to control the whole nation.
Q. Will instituting some sort of access trail or ID verification for non-mainstream political web sites restrict their free speech rights? Will this kind of legislation harm minors because they were not allowed to get information about contraception without proof of ID?
A. You bet your ass it will.
They're targeted because they're the most vulnerable target. That's all.
The things that we can do are: implement the security procedures we already have. Airport security is a joke - manned by minimum-wage workers who are thinking about how long it is till their shift ends. I can't count the number of times that I have set off the metal detector because I was wearing hiking boots with a metal shank and eyelets. Did they make me take off my boots and see what it was that set it off? No. I said "it's my boots" and they waved me through.
And if you make a connecting flight on a twin-turboprop commuter, take a guess how much the first officer makes. $15,000 a year. There is no way we can really improve security until we are willing to pay the people in charge of it what our security is worth.
But the thing is that the goddamn fucking people will squawk like hell if airline tickets go up by 10% but won't mind strip searches before every flight. Morons.
The better analogy is: you're using secure OSs and firewalls; would you give the various police forces an account, and the root password, on all your systems? That way they can make sure that nothing bad happens to your computers.
You want to be safe, stay in bed. Feel free to volunteer for body cavity searches the next time you get on an airplane. The rest of us would like to lead lives of sanity and proportion.Sorry for the provocative tone of this message. However, nothing has changed about the security, or lack thereof, in our lives over the last few days. You didn't really think that something like this couldn't happen, did you? Or that the government was going to save you from something like this? So why a knee-jerk reaction for something that still won't keep an enormity like this happening again? Any two-bit terrorist could charter a business jet, load it full of fertilizer and fuel oil and fly that thing into DisneyWorld or Sears Tower or wherever the hell he wants. And there's nothing the government or anyone can do about it.
Instead, why don't we think about: what is it about our foreign policy that makes so many people around the world hate us so much?
On one flight in an airliner, the sun was abeam the aircraft, and on the left side; I had a window seat on the right side over the wing. I saw a shadow on the wing that looked a lot like Schlieren images of shocks I've seen [I used to volunteer at a wind-tunnel lab as an undergraduate]. I think this was on a B727, during cruise flight so it was not unreasonable that there be a weak shock on the upper surface. The shadow also moved as I expected a shock to move when small control movements were made.
Could that really have been a shock, or was I seeing some sort of condensation artifact? (I have seen the normal condensation effects - in wingtip vortices, flap boundaries, and even a cloud over a large part of the upper surface.)
Unfortunately I couldn't keep track of the shadow all the way to the first power reduction since it got overcast.
As 91.1 of the Holy Scripture says:
(Paragraphs (b) and (c) deal with off-shore ops. and passengers, respectively; 91.701 and 91.703 are foreign ops.) And pilots for hire can fly Part 91 ops, as in corporate flight depts.Whee! FAR Talmudic arguments now on slashdot!
The cool thing though is: much more flexibility. Instead of a needle showing you deviations from your course, they can depict a "highway in the sky" on top of the artificial horizon. Instead of a horrendously expensive mechanical HSI (Horizontal Situation Indicator, a moving compass rose that has superimposed navigation needles) an electronic HSI can show you a compass rose with nav. moving map, and overlay weather radar, terrain, traffic and lightning strike data.
And those LCD glass cockpits are much more reliable than the good ol' steam gauges. Don't get me wrong, I don't feel that my life is being placed in jeopardy because the airplanes I fly have steam gauges; but man alive, I drool over what those colour displays can do. (The FAA is a lot more conservative now, and these systems are much more reliable, accurate and readable than mechanical instruments.)
(For an example of glass cockpits for [almost] normal people, check out the UPS Aviation Technologies MX-20, part of the AGATE project.
A few things to keep in mind:
But the most important thing is: inertial navigation works just fine - especially if there are <20 airplanes in the world flying at those speeds and altitudes!
In fact, X11 is still vastly superior to Win32 GDI (or whatever they're calling it today). I work from home two days a week, and I have DSL. I use Unix/X11 for everything - which means that I can do anything I need to using any program on any machine (whether it's at home or at the office) from either home or the office. Working from home is identical to working at the office - except for the noise, the constant interruptions, meetings, etc.
That one feature by itself is enough to blow all the Micros**t crap out of the water. (Leaving aside the fact that X11 can do anything that can be done on Windows. You might say that "Program X on Windows does foobar, show me an X11 program that does that" but you will miss the point. The lack of existence of that program is not due to any weakness of X11; it's simply because no one has written that program yet.)
You don't really think that a significant proportion of Linux/Unix users today compile things from source, do you? (A few do - gluttons for punishment like me... but I like having the source so if some bug really starts to annoy me, I can jump in and fix it.) Everyone else I know runs some sort of desktop; on Linux, K or Gnome. On both those systems, when you want to install something, you click on it, a window pops up that you type the root password into, and voila! it sets everything up, including billions of annoying icons everywhere, just like you want.(If you really mean to argue for the Windows Way of "everyone is logged in as Administrator all the time" - well, I wish I hadn't typed all this stuff in, because there's no hope.)
Don't get me wrong: if Program X that you need is only available on Operating System Y, of course your machine should be running Y. We use programs, not operating systems. (Again, except for the aforementioned gluttons for punishment like me - I've been writing code on Unix for 20 years and I just can't use any other OS. And I do watch video on Linux - you just need a video card that XFree86 supports well. And yes, it's not likely that Mom will be able to figure all this out.)
But don't make airy claims about "X having clear limitations".
Knuth has an excellent section on how hard good crypto is to design, in Seminumerical Algorithms in the chapter on pseudo-random numbers etc.
It always boils down to money and stupidity. To stupid to know how hard crypto is; too cheap to hire people who can do it right.Hint: Speakeasy.
Another hint: their customers are paying them to transport packets. They can say "We will transport x packets per second for you." But why should they have any right to look inside the packets? Why should they be allowed to look at certain fields of certain packets of a certain protocol? Or, in a technical sense: they are paid to transport IP packets. Why should they be allowed to look at anything in the payload, like TCP or UDP headers? They paid for IP, not "TCP only, and only as long as inbound packets don't have the SYN bit set."What would your reaction be if the post office starting telling you that you're not allowed to receive a letter from someone that you haven't already sent a letter to? Or, if you get an envelope, and inside it is another envelope, inside which is the letter, then that inside envelope can only be pink, but it better not have a floral border.
What's "whinning"? Whinnying? Winning? Whingeing?(Are you getting paid overtime to work on the weekend?)
I just don't buy the attitude that my manager is my "boss" - if s/he makes unreasonable demands I let him/her know, and loudly. They can just as well distribute that document in HTML (hell, or even PDF) so everyone can read it.
But I just wouldn't take a job that required me to use Windows. They're paying me a shitload of money to be a Unix guy, and a Unix guy is what they're getting.
Of course I'm sure that in some states (I won't name any names but just point to the southeastern part of the US) all vehicles - motor vehicles as well as bicycles - are equal, but some are more equal than others....
By law, those things have to trip not just for motorcycles, but for bicycles as well. Those sensors have a part that is the most sensitive; in enlightened states (California and Arizona are where I've seen them) they paint a little picture of a bicycle on the road where the sensor is most sensitive.
If you have a sensor in your town that doesn't trip for your bike (motorcycle or bicycle) be sure to write a letter of complaint to your local municipal authority. To calibrate these things I suspect the technician just moves his Chrysler LeBehemoth on the sensor instead of doing it right.
How do you drop an egg three feet, with no padding etc., and not have it break?
Drop it from a height of four feet.
Civil aviation uses GPS - a lot - for navigation. It's not just a toy for bored geeks in cars.
It's true that airliners will never navigate solely on GPS; a complete shut-down of GPS will not [should not] lead to any airliners crashing into mountains. However, too many private pilots do rely solely on GPS.
While global loss of GPS will not lead any airliners to mountains, it will lead to massive saturation of the system. For example, on Oceanic routes (trans-Atlantic and trans-Pacific) having a GPS sensor allows you to meet a higher navigation performance rating which means you can use the preferred tracks.