Battlefield 2142, and possibly several other online games from Electronic Arts, come with a CD key that can be used only once.

I just had a bad experience with Electronic Arts: they want US$10 for a new CD key for Battlefield 2142 because the one that originally came with the game was already registered (by the original owner) and they refuse to supply a new one or erase his account.

More information can be found by going to  serialreplacement.ea.com  or searching for "nominal" on their support site.