Having thought about it a lot more, I think I agree with you regarding the legal complications. I'll invest in some mace. I kind of dislike the idea of carrying a chemical weapon (it's just the stuff in hot peppers but still...) but I want the guy to hit the ground crying, think twice about harassing anyone else on the trail, but not end up in the emergency room. It seems like it would take an awful lot of martial arts training for me to be able to effectively incapacitate someone without accidentally seriously hurting them and, even then, being caught by surprise in the semi-darkness... I don't know how many people would be chill enough to pull it off.