IMHO, there nothing that will be perfect. I use python locks. They will need a hatchet or a saw to cut the tree down to take the cam. So I try put put my cams on big trees. A hatchet would probably be able to at some point breakt the cable as well.

The best thing I think, is to have the main cam on one tree and have a IR cam pointing down from anther tree at your cam, and maybe get the pic of the perp if its stolen.

Bottom line, if they want it, they are going to get it.