What to do about people harring my dog?

I live in Ga and I have a Pit Bull, she is voice trained, she is defenatly a great mascot for the breed. She has more patience and tolerance then any dog. I think sometimes she understand exactly what I say..lol...but we been living in this residence for 5 months now. She has 2 acres of fenced property to run on, but before when we were in the process of fencing the property, the people across the street come let her off her runner (she was never on it more then 30 minutes and I was always out with her..its over 75 feet from tree to tree plus her 7ft lead) and then called the humane socitey saying she ran them down the driveway. I was standing at at the top of the hill and watched them and she did not run them she did quite the oppisite she come straight to me. Well I called the police and they said I had no proof and I had to show proof of rabies. Which is no big deal. Well since then they have stopped infront of my house yelled at her, throwing rocks and sticks at her making her bark. Tonite two guys even went as far as going to the fence to try to feed her something and take her. He got ahold of her collar but she got away, when I yelled they took off back to they're car. My aunt behind me has watched them set in they're driveway and yell and throw stuff at her making her bark. What do I need to do to stop these people? My baby girl does not have an agressive bone in her body, my moms 6lb beagle mix dominates her and she is 50lbs. I know the breed very well and have owned them my whole life. I've never had to deal with people like this and idk what to do. I have private property signs and beware of dogs. Any ideas?