Is there any etiquette to hotlinking images from third parties?
Never appropriate, IMHO, without asking for and receiving permission. If you link images inline and your site/post/whatever gets a ton of traffic suddenly, you could potentially crash someone’s site or cost them real money in bandwidth overages. Plus, it’s just bad form. I use .htaccess file methods to keep my images from being hijacked like this. I’ve found that a lot of people don’t really know not to do this, etiquette-wise, so I usually send people nice emails asking them to stop [90% of which go to livejournal users without their own webspace to put images in] and then if they don’t, I replace the image with raunchy porn.
Actually, I don’t see much of a problem with hotlinking images on major news sites and the like. I know many would disagree. Never for personal sites, though, I concur. I’ve also had the problem that quonsar describes, and also have been known to replace the outbound images with icky porn, before I was given access recently to the very useful tool at Hosting Matters that does automatic redirect of externally hotlinked images from my site (with customizable domain exceptions). Before that, it was a massive bandwidth eater, as I’m lazy as hell about checking on things like that.
Rather than just replacing leeched images, I use Apache’s mod_rewrite directives to carefully redirect images from their original to a context-appropriate replacement. My favorite trick for loathesome livejournal users is to substitute the image for text in a font and color identical to their page design, such that it appears to be a normal entry. The new text, however, is generally about sodomizing goats or thereabouts. Gets the greatest comments from their friends…
