I simply let them know they are too close. if the friendly jesture doesn't work , I just keep fishing. People been crowding mefor years. I jst keep fishing.
One time , two gys set up right down current from me. they toss out bait when I've been jigging there for hours. I tell them they are too close and that i will be tangling their lines. they ignore me but one guy says to the other "if he tangles me he'll lose his jig , I got 30 LB mono on my reel"! I just kept fishing....I was using 50 LB Cortland SPectron!
After a couple of tug of wars....they left!