Homeless (not) tax-evaders made for an interesting breakfast read. Initially, anyway. The story went in another direction than I anticipated. In No. VA, generally neighbors call on each other about parked cars, dog poop* and their kids entering the invisible yard line.
If the cop wanted to get them on loitering or something, they wouldn't have laughed.
If they are not on your property or threatening you, I say, leave them alone. If you do anything, they could retaliate. (*reference neighbor disputes about poop & dogs)