According to a posting made on an anti-STEAM website, a 22 old Russian hacker aka MaddoxX has bypassed Valve's security system and accessed a significant chunk of data, including:

• Screenshots of internal Valve web pages
• A portion of Valve's Cafe directory
• Error logs
• Credit card information of customers
  
• Financial information on VALVe
  

While only the Cafe owners appear to be in immediate danger, MaddoxX claims to "have shell access everywhere" and has posted a list of login details for accounts on the VALVe servers, and private certificates for "People with a little bit (sic) experience ... create their own 'fake' but working cafe / certificate."

Complete Story at dailytech.com