If some old lady was to call the cops and say that a man was walking down the street with a boom box on his shoulder, would they send out a car?
How about if she said a guy was walking down the street with a dog on a leash?
No. They would not send out a car. The operator at the station would say, "Ma'am, there is nothing illegal about that", or something similar.
If you call and complain that someone is washing his car or cutting his grass or taking a sunbath or clipping the hedge, or any number of LEGAL ACTIVITIES, the cops won't send out a car. At least I hope they wouldn't. Why? Because nobody is doing anything wrong.
"But they got a call. They have to check it out!!!"
Check what? No crime was reported.
So why, when the little old lady calls and says, "There's a man walking down the street in front of my house and he's WEARING A GUN!!!!!!!!!!!!!!!!!!!!!"
Why don't they just say, "There's nothing illegal about wearing a gun, ma'am."?