OK I will keep this short, Steam forums were hacked the other day. The hackers were able to gain access to Steams back end systems - amazingly they have no
idea if any card details were stolen but they do know that some user details were taken..
Advice....
please take our suggested advice and this applys to any online store in the event of an hack or account breach...
* Change your Steam password, just in case. If you were
using a weak password before, take this opportunity to choose a decent one.
* Keep an eye on your credit card statement and report
any unexpected transactions.
* Consider not storing your credit card data on Steam's
servers. You don't have to. You can choose to enter it every time you need it
instead.
* Consider enabling Steam Guard. If you do, Steam will
email you every time you (or someone else) logs in from someone else's
computer.