Seems like there's a problem here? From looking at a couple other users, Petr's rating is also wrong.
BTW look at my graph for the real rating (2418).
EDIT: Azret linked a blog in Russian, it seems these might actually be legit :O
http://codeforces.me/blog/entry/44168?locale=ru#comment-287807
EDIT 2: And it's back to normal [for now].
EDIT 3: And it's changed again, totally differently this time. In particular the top rated all seem to have lost rating.