About 15 years ago when I first bought my property, I had some kids ask me if they could come to my place to fish. I told them I didn't mind, but would like to talk to their parents about it. I also gave them rules such as they had to clean up any trash and they were not to start any campfires nor bring any vehicles onto my property unless they used my road. The kids were pre-teens and just seemed like good kids that wanted to have fun.
I never saw their parents, but I would see the kids from time to time and remind them that thier parents had never come to see me. As the kids got older, I realized they were avoiding me and coming onto my property by a round-about way where I could not see them. One time I found a 4-wheeler that had been hidden after using a secret trail they had made. I found the kids and told them remove the vehicle and not come onto my property by the trail.
Then, my neighbor told me that the kids (now mid-teens with several friends) were coming onto his property across my property and were using his fishing dock and making a mess. When confronted, they had told him I gave them permission.
A couple of months later, I discovered two boys and an older man fishing from my property and my neighbor's property. Their car was parked beside the county road and they had used their trail to come to my property. I told them all to leave. The older man turned out to be the father. His first reaction was to tell me that he had a right to be there, I couldn't believe how indignant this guy got and my neighbor who was witnessing all this just shook his head at the gall the fellow displayed. I told the fellow that I would let him discuss his position with the county sherriff, but that he was a trespasser without any rights on my property. I also suggested that he had entered my property right beside a no trespassing sign and used a trail I had specifically forbidden his kids to use.
So, at that point, he started calling me all the foul names he could come up with and began to walk away back across my property. I called him a tresspasser and noted that there were lots of witnesses there who would verify my story. To that he threatened me by saying he was leaving, but would be back to take care of me.
With that situation, I knew I should call the sherriff, and did. The guy was so stupid he went home and returned to sit along the county road in his car to intimidate me. He was still sitting there when the sherriff's deputy arrived. He quickly started his car and left as the deputy pulled down my driveway. I told the deputy about what had happened and he went to have a talk with the fellow. That was the end of my problems.
That's what happened with me, and I would suggest that what seems like an innocent use in the beginning can change into something ugly. Kids grow up and if they don't know you well, you will not be any kind of authority to them. I would not do it again.