Police people using offensive signs? No, my partner born deaf still uses these signs as do her deaf club peers, it's about context not everything is about discrimination. He is targeting the wrong people, the signs originate WITH the deaf.
Note: black sign colloquial usage use a 'negative white' sign format also, should we not call that discrimination too?
Politically correct signs or, those newly created to replace perceived racial negativity etc ignore where the signs originate aka with the deaf themselves, and whilst new signs are replacing old ones, older deaf are not using them and still using the signs they know. It won't help the police going at these deaf too which is what the poster is asking for.