Valve Doing Something Wrong Again

Valve Has Banned over 20,000 STEAM Accounts linked to people trying to pirate Half Life 2.

I don't feel this is just.
Imagine someone has legitimately bought every available title over STEAM. And then for whatever stupid reason thinks it would be a good idea to try the warez version (everyone makes mistakes). His account is banned and he now can't access his warez copy of HL2, but what I think is wrong is that he also can't access any of his legitimately purchased games also. That right there is a step over the line for me.
If they allowed people to purchase a legit copy copy to unban their account, fine, but they aren't. All the money people have invested in their STEAM accounts has gone down the toilet just because of one mistake, and to me that is stealing from customers (the worst thing a company can ever do).