With the PlayStation Network having its security compromised, many users of Steam who linked their accounts up on the PS3 or PC, are worried about their security too.
However, Valve has made a rather simple statement which should allay the fears of many users. It said: "Steam has nothing to do with the PSN outage."
In other words, if you did link up your Steam account with your PS3 so you could take advantage of Portal 2's extra functionality, you have absolutely nothing to worry about.
Source: Giant Bomb