Sites like Reddit are complicit - they /want/ to be a forum for this. It's not hard to spot this kind of thing if they wanted to stop it. This is exactly what Digg did (and that destroyed Digg - Reddit now, too)

Yeah, that shit is big business. Not surprising since Reddit gets more views than most TV stations and studies have shown that people regard wed forums as being more "true" and less corruptable so they take the information with less skepticism.