From what I was taught years ago, private property signs meant nothing in my State, at least as far as enforcing the trespassing law. As I remember it, the signs had to read: No Trespassing and I think there were other details as to where the signs had to be and how close together.
I have had to run people off my property at various times. If they cut my fence, the law WILL be involved. If they used a gate and leave without too much hassle, I just ask them to not come back.
The worst ones are the dumpers and the shooters. They come out from town and just think they can go anywhere and do whatever they please. I try to educate them, sometimes a little harshly.