There was some exploit that involved cloning an HDD and running backups. I think a firmware update killed it, though. And are you referring to game sharing? That's essentially by design.
Don't think about some guy downloading an iso off a torrent. The real factor is if organized crime can make money off pirated games. Throwing around facts about the cost of media or the time to record is mostly immaterial. In some markets original PS3 games are over 150USD. I personally know several people would LEAP at being able to pay just $20-$30 for a pirated PS3 game. There's a market there, it's silly to assume there's no interest in pirating the PS3.
Crime goes the easy route when avalible. Why spend so much time and money getting ps3 copies up when you can make 20 copies of a 360 verison in the same time as 1 ps3 verison. Even if a 360 game will go for just $10 compared to a $30 ps3 game. Your siting on 20x10 = $200. $30x1 = $30. And like i've said the huge majority of games have also come out on the 360.