I agree with you StevenSeagal. As far as I know only cracked game users had same CD key obviously. Origin and DVD version users (I always had both options tested, not Steam though) never had that problem with autentification unless they gave their Crysis DVD to a friend or family member to use on other PC and both tried to enter the same server at the same time. Otherwise everything should be fine (is it possible that crackers are using CD key from private DVD?).
So I don't understand why steam users would have this problem with CD-key. Game cracking is not supported here because of moral and copy right reasons. But it depends only on users. Having original version of the game is the base here to start with. The price is around 5$ sometimes Origin/Steam/DVD - which is nothing comparing to 10 years old MP game, better than most of new MP games - still after years. So only if somebody has original copy of Crysis and still has problems - he needs to try other options to fix it. But there will be no help and support for cracking games just to have more players (ignorants, crackers and hackers). If somebody wants to use cracked Crysis - it's his problem and his responsibility, we can't be his daddy. Also giving advices like - "download cracked version" is against the rules here. I know what some people think about it and about my opinion - But I'm just saying to make it clear.
Besides - No one can call himself a lifetime game fan - when he didn't even pay 5$ for the game, even once in his lifetime. Unless something is wrong with his priorities and... ideas for respect to the creators without who he wouldn't have the game :) Even if creators don't respect players in many points - still they made the one of the best MP games. No doubts about that :) So at least having one official copy of the game is worth it :)