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Dealing with Deep-Linking to Your Online Photos?
Pig Hogger asks: "I've had my own hobby website since 1993, and over the years it has expanded to be quite a reference for the domain I am covering (some pro websites list it as additional reference, and so does Wikipedia. Google page-ranks it amongst the top). Every so often, I peruse the logs, most especially looking at the referrers to see where people come from, and once in a while, I notice that some webloggers deep-link to an image on my site. I do not mind too much when it's on-topic, but when it's not *AND* it's sucking-up bandwidth, I tend to be irked. Or worse, when you can't go look at the referring page without registering on the weblog site. In those cases, I change the picture filename (and the corresponding webpage that calls it), and I substitute a smaller (and most often, naughty) picture. What other tricks those of you are facing the same problem have to address this problem?"
"Deep linking" is what makes the web the web.
Free as in mason.
Preventing people from *copying* the images is a completely new challenge, and fortunately most people don't worry about that too much.
Deep-linking is more dangerous than copying, because it can unexpectedly cause vast increases to your bandwidth if the image is redisplayed in a more popular location.
Copying... well, it's annoying if someone else uses your photo on a site w/o crediting you, and especially annoying if they are selling prints or something like that, but neither one costs you money (remember, you were displaying it for free), and in both cases they are violating copyright, so you can complain to their host with some reasonable hope of action.
If you're actually a good photographer and are *selling* those photos, then you need to look into ways to make them hard to copy. The obvious is only letting people preview a low-res or plainly watermarked version. You can use that annoying trick of catching the right-click event in JavaScript and popping a copyright reminder notice. You can display a transparent gif *over* the actual photo (defined in CSS instead of an image tag), like Google does for their photos of copyrighted book pages.
So you can tell wget to lie to the web server when raiding your favorite web page for images.
:-) At that rate, it's probably easier to mirror the image. Problem solved.
That's not what the person asking the question asked for. He wants to stop sites from deep-linking his jpegs, not protect his nuclear launch code CGI to be used only from his own home page.
A simple filter which would require the referer to be on his web site would pretty much stop his problems anyway. The people deep-linking to his web site write their web pages for browsers with <img src> tags, and as far as I know, you can't in HTML tell the web browser to fake a referer header. Then again, I'm not a HTML-head...
And it's not really practical to tell your user to use wget to download your web site either.
May I make the following suggestions?
and later the key value may be different. That way, you don't rely upon a spoofable header. Yes, this makes your image non-cachable, but if you are using referrer blocking, perhaps that is not a bad thing?
www.eFax.com are spammers
No, it's very strong protection. You seem to think that this is some sort of anti-copying measure. It's a way of protecting server resources. Nobody's going to bother deep linking when 99% of their visitors are going to get broken images. They'll just copy it to their own server instead.
Why on earth would somebody do that instead of simply copying the image to their server?
I used to be the webmaster for a fairly popular (in our particular niche) website with an online store. I got pissed off when I started seeing people putting things up on eBay with IMG tags pointing at our server. So I did what many of you have suggested, set up a mod_rewrite rule that if the referrer was not blank and not our site, it substituted a "Copyright Violation" JPG file (The bosses probably wouldn't approve of Tubgirl or the Goatse guy). I had to discontinue this within a week because a fairly popular BSD router software (can't remember which one, sorry) used to include the IP address of the router in the REFERRER field, and so quite a number of legitimate viewers were getting "Copyright Violation" images in place of ALL the pictures on our site. And the worst thing was, it used the PUBLIC IP in the REFERRER field instead of the private NAT address, so I couldn't even add an exception for NAT space to fix it... After spending another two weeks looking around, I just started banning sites one at a time (eBay...) from being in the REFERRER field and keeping an eye on my logs. PITA, I know...
That was a few years ago, perhaps this is a non-issue now. But keep in mind that people running braindead routers or webcaches might inadvertantly trigger your rule and get pissed. If you're just a hobby site, no big deal, I guess. But if you're making money off the site (online stores and the like) you risk losing business over it.
Plus the whole refering them to tubgirl and other "shocker" stuff has always been, in my opinion, a little extreme.
If I were a simple webhost client with a bandwidth limit, those links would most likely have put me over my limit. Fortunately, the server I have is colocated at a rather large colo, and we don't pay much for bandwidth, so it only really came down to a few dollars (basically it cost me a day's worth of my usual decadent lunch).
Yeah, it's extreme, but putting an image on someone else's server into your sig on an absurdly popular message board is also extreme - but they don't realize it. I certainly can't e-mail them and say 'please don't use my image', and I shouldn't have to waste my time making a 'don't steal this image' image for one site. So, I just used what I had, managed to wget an image without having to look at it, and voila, problem solved.