The hacker is from Albania. He made a post on Battlefield Heroes site & said: “Hello all Players and Admins. I’m Why So Serious?” He also have a facebook page, where he publish the hack details. Hacker claim that he will hack another EA Games accounts and Jagex Games accounts also today. He will post those accounts also on his facebook page and forum forum page. The hack details are posted on pastebin from Battlefield Hero site and will be published today.
Source: https://thehackernews.com/2011/09/ea-game-battlefield-heroes-accounts.html