One site was selling Russian Steam-redeemable CD Keys acquired with Stolen Credit Cards. Some accounts got temporarily suspended for redeeming those keys, while others just had the games removed from their accounts. Of course, they never got any refunds from the sites selling those keys.
A MOD here on GAF, seeing these events, banned mentioning of any sites that sell russian-based cd keys (in other words, cheap cd-key only games), and some legit web stores (like Green Man gaming) got caught in the crossfire.
Either way, the point is moot nowadays, because every Russian game is region-restricted to Russia. However, some shady sites (and the one posted on this thread about x-com is not one of those) still sell keys bought with stolen credit cards. They're not as cheap as they used to be, but you can easily tell which are those websites (misspells all over the website, poor translations, poor interface).
The site i'm talking about still sells cd keys, and I'm stuck in their mailing list. I can't remove myself from it.