Yep, California (I believe) was the first state to inact this practise. I havent heard mush "noise" so I have to assume its working. If you think about it.......Its not that hard to estimate speeds especially when you are driving and you know your own speed. Its really an integrity thing, but as I say that I remember getting a ticket from an Alabama state trooper. He showed me the radar gun 80 in a 55! He said he was going to be nice and reduce it to 69 in a 55 so I didnt have to go to court. the real truth was I was running right about 60ish and he was lying to make a quota, and he had proof but no integrity