Wow, the mention of Lonny brought back some memories. He had a bad habit of spying on me and my hiking companion, a woman, when we would go upstream from the springs just to escape the crowds. I believe he thought we might be having sex and he wanted to watch (we weren't). I warned him to get lost several times but then would get a feeling that we were being spied on again and there would be Lonny, hiding on the hillside.
On a subsequent visit I brought a slingshot and a few painful hits convinced Lonny to leave us alone.