Social news sites are becoming hot-beds of shilling. Shilling is the act of pretending to like something, in order to convince someone else to take an action. (There's a fun discussion on the talk page of the Wikipedia article named "Shill" about exactly what activity should be classed as shilling, and what activity is just lying. I tend to take an inclusive view on the subject: if you're lying to try to make someone think something is better, you're shilling.)

Niall Kennedy has a lovely blog entry about how he was able to track down the back-story on a couple of shilling attacks on the news aggreggation site digg. His article contributes two particularly fun parts of the story: