Saw this today:
Source: LinkGreetings community,
It's clear that Call of Duty: Modern Warfare 3 keys have absolutely been compromised. We will now permanently ban users that submit them as giveaways. Going forward, only submit giftable copies of Modern Warfare 3. Please do not submit keys even if you believe the key to have come from a reputable source.
Thank you for your cooperation.
-regards
So right now if you see any offers or your friends offer you a raw CD Key for MW3 for PC Steam, Disregard it. Better safe than sorry. I'll try to dig up more info but it seems like its another round of the Dirt 3 incident a while ago.
I Dont know if Steam will remove the Licence of users that are using the exploited keys or will ban them for exploiting. So as of right now if it aint from a actual walk in store like GameStop or Steam Dont touch it until this has all blown over.
Thought Id Give EP the heads up!