I live in Pennsylvania my whole life except for 15 years I spent in New York. In New York you just cannot have a scanner in your car but as a newspaper man I always did and it was seen by multiple policeman who never batted an eye.
I'm back in Pennsylvania for about 38 years, it's legal to have a scanner in your car.... period. I bet you if you ask any policeman in my area in Pennsylvania including a chief of police, if it was legal to have a scanner in the car every single one of them will tell you, no way, it's illegal and you can't have it... because that's what they think it should be... but they have no idea what the law really is.