If you've never cheated in Team Fortress 2, I have some good news for you...
http://teamfortress.com/post.php?id=2787
There was a small TF2 update today that is going to fix the problem of people using external applications to go idle so they can earn items. If they've ever used these applications, then they lose the items they got with them, and their account gets flagged. On the flip side, if you've been playing legit, you will get an angel halo called "The Cheater's Lament" as a hat for ALL of the classes. You also get a message explaining why you got it. You may not see it immediately when you jump into TF2 today, but just keep playing. Mine showed up about 20 minutes after I started playing today, and it happened when I was ironically talking to someone on my team about the halos. So, did you get a halo?