Oh, it happens.
Valve also has an "infallible" automated anti-cheat system with zero-tolerance bans.
Think about that for a second: Valve employs a program which, if it thinks you've cheated at an online game, will ban your Steam account, and there's nothing you can do about it, because the system can supposedly never fail.
That is, of course, unless it fails spectacularly, and all at once, as was the case with the Modern Warfare 2 bans, which left thousands of legitimate Steam users permanently locked out of their accounts, with Valve shaking their smug heads, saying, "There's nothing we can do, it's INFALLIBLE."
When press got bad, Valve did what they always do to win over gamers. They pushed digital software for nothing, gave away copies of L4D and re-activated the accounts. It's how they won over gamers in the first place: everyone hated Half-Life 2's single player campaign being saddled with online activation, at least until Valve was all, "Watch for falling prices!" and put out a dirt cheap Steam sale or two. After that, everyone was eating out of the palm of their hand.
And the fact that you can lose the right to play your legally purchased Steam games because of a random glitch in their system? Immediately forgotten.
But man, L4D is cool!
