I truly do not understand the stupidity of some people.
Seriously, folks, is it so difficult to just leave the stuff at home? I would never, ever put anything like that even NEAR a screen saver, desktop picture, USB key, etc. or in the same folder as a public presentation.
Apparently this must happen a lot, because in addition to stories like this one (in which all the victim got was a good dose of embarrassment), almost every week I hear another story on the news that someone was arrested at the border, because customs officials discovered a laptop full of, well, the illegal kind of porn. I wish I knew a customs officer - I'd want to ask how often they stumble on the legal stuff and wave the guy through, snickering under their breath...