I been following this one and not sure if the post is real or not. Does seem fishy.
But for the subject matter at hand. We have always approached and confronted people that trespass. It's just the way you have to do it in some areas. No one means be an ass about it but the individual needs to understand you aren't gonna put up with it. If your afraid to address an issue with someone on your own land then you have an issue.
On a side note, a rock can do some severe damage and even kill a person. Don't need to be softball sized or the victim needing to be prone. One good throw is all it takes.