CheesecakeRecipe
Stormy Grey
It makes sense - I see people getting duped all the time trading for games purchased by credit card scammers. This should prevent games being traded away and later revoked which (although it never happened to me personally) I guess is a real hassle for a lot of people. This is just another "we have to do this to protect people from themselves" for those users who think you really can get that copy of Day Z for 2 keys.
It'll be interesting to see what effect this has on TF2 key trading.
It's a heavy-handed solution to the problem. I am not too big of a fan of removing and limiting people based on what the lower end userbase too often falls for. This is going to murder pacing for traders during sales.
This also doesn't seem to cover the idea of gifting the game to someone - they can still just as easily do a chargeback to fuck you.