AdRants has an post about people being upset about ads on Flickr. People seem to be blaming Yahoo! for this practice.
With Yahoo's purchase of Flickr, it didn't take too long for Yahoo text ads to begin appearing next to Flickr member's pictures. Unlike Google AdWords, Yahoo text ads, at least on Flickr, appear on personal Flickr pages whether or not the member wants them. Granted, Flickr provides the service for free which negates a non-paying Flickr member's ability to completely control what appears on their photo pages but one Flickr user, tanais, doesn't like the practice, commenting on an ad placement next to an image of, we assume, his dog, "I do not like my pictures being used to advertise a specific breeder (they may be excellent they may be terrible - that's not the point)... so I shall sit down and think about how best to AdBust this." [AdRants]
IMHO the people complaining are idiots. I've been a user for ages, and Flickr has always had ads for free accounts. It's been one of the big selling points for their Pro accounts. I'm not a fan of advertising, but you can't expect to get something for nothing.
Flickr is one of the few web sites that I think does get it right. And my Pro account has been a very good deal. If it's that much of a big deal pay for the service.