Earlier this Week, Steam forums was taken down due to hacker attack. Apart from forum security being compromised, Steam's database containing user personal information was also breached.

Hackers did get access to the server containing user credit cards and user information, but according to Valve, there is every possibility that Credit Card information was stolen but there's no evidence to confirm it.
"We do not have evidence that encrypted credit card numbers or personally identifying information were taken by the intruders,"
In an email response, Valve's Gabe Newell said that all personal information of Steam users was encrypted using AES256. Gabe also confirmed that users will be compensated with the free copies of PORTAL 2 and DOTA 2 very SOON.
