He may have committed at least 2 violations of law with those signs (at least where I come from). 1 if he posted the signs without the consent of the land owner. And 2 for posting incorrect information on the sign itself. I tend to agree with Swifty that it may be time for you to contact the dep. You could also talk to your landlord to advise him of what's going on. He may solve the problem for all of you once he knows. Also, in my home state, NY, "charging for access removes the liability protection granted to the landowner by the General Obligations Law". You may have something similar in your state and your landlord may not want to take a chance with some unstable hunter. Just saying