Warhead has Spore DRM, Limited Installs
Keeping in line with its other titles, EA has included the same DRM with Crysis Warhead that was built-in with Spore, disallowing the user to install on no more than three computers.
Additionally, the company’s EULA for the game states that “CRYTEK reserves the right to periodically validate your license through subsequent online authentication.”
So, it’s confirmed then: EA doesn’t trust its customers any more. Or maybe PC piracy is so bad that even those who buy the original copies are not to be trusted anymore.