There's a
fairly recent thread [webmasterworld.com] about "facebookexternalhit" from the user-agent ID side. Basically the thread confirms that we're dealing with another variety of hotlinking-- an annoying one, because you have to make a separate RewriteRule with its own RewriteConditions to deal with them. (Maybe I need to do something about their preliminary robotic sweep, where they pick up the whole page including the one image that will be hotlinked. But that involves close peering over logs to see what I'd have to do to nip them in the bud. Ugh.)
But it doesn't answer a Curiosity Question. I am one of the two people on this planet who isn't on Facebook.* Can someone explain exactly what leads to this particular variety of hotlinking? That is, what activity on whose part? What does the user see? Where (within Facebook) is the hotlinked image coming from? Why can't Facebook just park the blasted image on their own site?
That was a rhetorical question. * I can't say FB because to me that means FutureBasic. Sorry.
