A new study by Pew Internet and American Life reports that 9% of social networking youth have had an "embarrassing picture" of them posted online. In addition, 16% reported that they have had a rumor spread about them online. Although the content of this cyberbullying is not sexual by default, the content of rumors often is about sex. As for pictures? They could range from partying (or, more likely, its after effects) or just a picture showing someone's "bad side." But they could also show people hooking up or pretending to be a Girl Gone Wild.
When conducting my own interviews of college youth about their use of social networking sites, I heard of a group of guys who contacted girls for anonymous sex. While the boys were receiving blow jobs, they took pictures of the act and posted them on their MySpace accounts -- and showed off the evidence of their conquests to anyone in the dorm who cared to see. Another group of guys turned on their webcams before taking a girl to bed after a party. I am not sure what happened to those videos.
Point is, it is really easy for "embarrassing pictures" to end up online. Is it more common among high school or college youth? Who knows, but the long-term effects can be serious and devastating -- not just humiliating.