I always thought there was nothing harmful about it until I read this post from Yahoo! Answers: I read the whole thing, and it sounds like it's extremely dangerous. It's weird though because I ahd mine jailbroken for over a month, and experienced no problems at all. But I'm now un-jailbroken due to me updating to 3.1.3 anyway... I never knew it did that much harm... What do you people think of this?