And then, finally, go back to those ordinary, non-www-professional humans and present them with the concept of a webmaster blocking a search engine, thereby preventing the contents of your site from turning up in search results. I will be very surprised if the reaction is anything other than "Huh?" and its synonyms.
I personally don't care what people think; I am making a rational Homo economicus
decision to block my images from search engines in the future. Let people find me via regular search and actually visit my website.
I'm angry that Google doesn't provide us with some elegant way to opt out of showing large images, so I have to go with the next best thing which is a brute force htaccess & robots.txt solution. But at least there IS a solution, even if it's scrappy.
I'm not spiteful about it, I looked at the pros and cons and decided on a logical course of action.
They changed the rules of the game; I'm changing my own strategy accordingly.
I think anyone who, like me, has an image-based website that no longer gets noticeable traffic from Google Images should do the same - at least their images are protected from scrapers and pirates when they no longer show up in Google/Bing Images, at the cost of negligible loss of traffic.
On one hand, the 150 visitors/month I get from G-Images (compared to 10,000 a couple of years ago) is worth about 10 cents in AdSense revenues. On the other hand, wasting my time filing complaints with Google when pirates use my images for search hijacking and Trojan injections is costly and irritating.
Just a rational decision. I know I'm not punishing Bing/Google. I'm just looking out for my own interests.