I am not very knowledgeable about trail cameras or keeping them from being stolen. I also use them only on private land but trespassers sometimes walk thru. I have scrap lengths of fairly light chain that I wrap around the tree and lock to the cameras. These are Browning cameras that have hole to lock the door closed, I always put a lock on them and include the ends of the chain in the lock. I try to cover the chain with old camo material so it won't be so noticeable. If someone steals the camera they will have to cut the lock or chain or the camera door to get it. Mounting them high has been suggested but I haven't been doing that. So far none have been stolen but I don't use them much and do not leave them out for long. I try to place them where they won't be easily noticed, if possible.