Friendster did something weird, that a lot of people probably still don't know about.
I found out, oddly enough, via the promising new U Chicago Law blog.
You have to opt out if you don't like that, via the My Settings menu.
They should have made it opt-in, in my opinion. It didn't really affect me; I'm barely on Friendster anyway, and I can't say I'm sneaking around checking out people whilst they are unawares. But, still. I bet a lot of people got burned.