None of this sounds desirable.
I thought the image search was an inconvenience as a surfer (I found, I get less spammy results for an image search than regular search - but with this new format, it's hard as hell to get to the page that sourced that image! Often times I give up.)
As a webmaster, this is not good at all.
You can save bandwidth by rewriting to a single-pix gif when the referer is "blank.html". Set its expiration to right away, and if the searcher really does take the next step, they'll get your real image.
Is this in the thread tantalus linked? I've bookmarked it for a detailed read later tonight.
However, a large percentage of the regular traffic at the moment is referer-less, I'm only able to decipher this type of traffic from legit visits by the 0-second visit length.
So rewriting based on referer only solves a small percentage of the overall problem.
tantalus - Are you anticipating a rankings impact (both organic AND/or images)? I get some decent visits from images (both bing/google) - but nowadays that's few & far between, but they still trickle in. Guess a lot of people also have a hard time accessing the source page, too.
I really don't want to remove my images from Google & Bing, my images rank well on both engines - but if they are giving phantom traffic the rankings are essentially useless. My images aren't the type worth stealing, but rather, they grab attention and bring the user for the surrounding content.
I guess this is a ploy by Bing & Google to keep people on their site longer.