Apparently someone has succeeded in using "bots" - computer programs that make all the decisions - to beat some of the small stakes games on pokerstars. It looks like the jig is up now though. It also seems like they did a shitty job with the tactics based on some of the moves they had the bots make.
Here is the full story.
I talked to a guy in Vegas once who had created a bot and tried it out. He said he let it run for about 8 hours in three $.02/$.04 cent limit games. At the end it was ahead a total of about $30 which is 750 big bets! That would be $15,000 at $10/$20! He said they caught him the next day and closed his account.
I'm sure there are some other bots out there, but for the most part, I'm not worried about them getting the best of me. And even if I knew for 100% sure that there were lots of the most advanced bots constantly playing in the exact games I play, it wouldn't stop me from playing since I'm winning anyway.