Thats a good question. I think the reason people dont get hit is becasue they dont want to hit you, they just want to scare you away. Not that I dont think they probably take a person on a rare occasion as a meal in some places when they are really hungry. (Lots of missing people that have never been found), but doing it on a regular basis brings unwanted attention.

I think rock throwing is how they hunt most of the time and they probably are deadly accurate with good sized rocks. I think they probably can make leathal head shots at will.