Years ago, my father lived near Town Creek Marine. The fishing areas there would get overrun quickly.
One morning he was enjoying coffee on his back porch, and two men came walking up the drive with fishing poles.
Dad "You can't be here, this is private property."
Them "We fish. We fish."
Dad (as they continue to walk) "No, you can't fish here, this is MY property."
Them "We fish. We fish."
Dad (Walks inside, gets his shotgun, points it at them) "Me shoot. Me shoot."
They high tailed it out of there, and he never again had any problems.