I've had people go as far as saying "The last owner gave me permission to hunt here the rest of my life, if YOU have a problem with it, you need to speak to the people you bought it from." To which my response has always been "They don't own it anymore, I do. I have a problem with it,and the sheriff has the cure to that problem. It involves you in jail. Any questions?" So far, with the exception of the one time I had to call the sheriff and he came out code 3 (Lights and Siren), it seems to work. I haven't had any repeaters. But unless you live on the land you hunt, you'll never keep all trespassers out. Although someone in this forum told me last year to post "Color blind hunter on site, shoots at sounds. Enter at your own risk" signs which might also work.