I don't think it does, you can buy CD keys from people but they have to send you the actual CDs for the game. But it may because if you bought the game you'd have the keys.
I said id buy w/ GR points or if no one is using one and wants to give it to me thats cool too. Niether of which have anything to do with warez.
I think that it's legal if it's an onlinegame like cs or something like that because it's mostly the cd-key that you pay for not the cd. But I think that you should wait for a mod/admin to answer your question.
No, you probably dont know what youre doing if your downloading Keygens with Viruses, thats not why they are there.... And as for buying CD Keys, I would want the Original Paper that the CD Key was on, nothing else...This way even if the seller tries to use it again, or hasnt Deactivated it (Like in Steam) Just Email the Help site with the Scan of the CD Key and you will get ownership of it to your account....Phew, Hope I helped