The Steam Users Forums (thanks Half-Life Fallout and Voodoo Extreme) has news that another 30,000 Steam accounts have been banned for attempting to gain illegal access to games that they had not purchased. Word from Valve's Erik Johnson is:

Valve takes such activities seriously and reserves the right to disable Steam accounts engaging in piracy, cheating, illegal activities, or any other activity in violation of the Steam Subscriber Agreement. The accounts that are disabled today will not be reactivated.