Far Cry 2 comes with a nasty copy protection. Actually, it’s more like a strict DRM variant that needs to be activated online and can only be used X times when not properly deactivating it.
You can manually revoke an activation without uninstalling the game by simply calling:
Easy, huh? I’d prefer Ubisoft to not use any of these bugger DRM crap at all, but then again we all know the story of software piracy (note: pirates probably have a better version without this crap, so this whole thing is totally beyond the point anyway!).