I wonder if you dont have a close friend thats playing jokes on you. Either way, if its not, whoever is on your land is tresspassing and can be arrested on site. If you can find out who it is, get yourself an updated platbook and show them the property lines as you walk them. Id move your cam to a different spot near by and see if you can get a better pic. Dont take anyone in with you though. It seems these people knew the cam was there. Who did you have with you when you put the stand up and the cam?