CD Keys on the net is Illegal to begin with..
Second, D.net (the forum you are looking at right now) runs the directory servers
Third the servers themselves check CD keys as you try to log in.
No same 2 CD keys can be on the Dyna at the same time. Servers won't let you log in. (that means if a person logs into a Dyna server, the key is registered with the server.. Later if someone else connects to Dynaverse 3, the servers CRC check each other for the CD Key and if the first person is online with that CD Key, then the other person is SOL until that player logs off (if they ever do)
So it is just something you will have to live with when using a Pirated key.
Or you can just go on Ebay and buy a game with a CD Key.. might cost ya what... $5.00 plus $1.50 for shipping?