Activision protect kick

Hi,

yesterday, I got kicked from the game all of a sudden. It said ‘kicked for Activision protect’. Since that moment, every time I enter the game, it kicks me after a few seconds.

Additionally, my nickname gets changed after these kicks to the name of a different player I don’t even know (I’ve only seen him a few times in the game).

So, what is wrong and what should I do?

Which Cod4x version are you running?
What server were you attempting to join?
If you could also include a screenshot of the error message that would be great.