Yeah, my account got hijacked yesterday. I had a friend who it happened to recently, too. I've sent in a support ticket but Valve works at their own pace, so it will probably be a while. For anyone who is friends with my steam account and sees this, don't click any of those links, it's not me.
Be careful for it, I've never had something like this happen to me. They've sold all my "valuable" TF2 items, and have played a few games that I own.