For those that had problems logging on to Steam earlier today, it wasn't due to a hacking attack or anything related to recent threats by a hacker group.
Valve had a nasty glitch occur that lead to people being able to randomly access accounts of others with some reports saying account info was locked out and others saying the opposite.
Valve claims the issues have been fixed but probably the best to change passwords and/or account details to be safe.
http://www.destructoid.com/-updates-...n-329492.phtml