I do not know and I am not sure if it really got hacked or it wants to make fun for all users. I logged in on April 1st, 2010, and this is what I see on the users section.
Almost are Lady Gaga and Twilight Robert Pattinson, depend on the gender of users. And they put one more application that you have to paste your password to give Llama Badge to your friends. I do not know what that is, but a good way to safe yourselves, you should not use that application. I did check on Google, my fav search engine, and I cannot really see any way to solve this problem for now. It might have some ways in the future.
When I want to change my avatar (icon), this is what I see,
Okay, I am not a fan of Twilight, and I do not hate them, too.