Hey RealMalatesta
What do you say "but all their Bitcoins have been withdrawn" ? Are you in contact with the support or with other users?
About 50 minutes ago I was in my account, the Bitcoin from my ballance were present. No missing Bitcoin at my account. I use 2-Phase autorisation for everything. RealMalatesta please write in detail what you know, rather than just spread fear... 
SwissMike Well what worries me is this:
http://www.cryptocoinsnews.com/news/btc-stolen-btcjam-ongoing-heist/2014/04/08Dude, it's a news from April --'