Mallard
Maybe this will clear up how they find them they are looking for them, the camera's are on the same trail elk,deer and man use to travel,(you wouldn't get many pictures in a place there is no trails) at low light the camera flashes as it takes a picture they see flash they take camera, There is only so many trees in the right spots to hang a camera that can take pictures of what is travelling on the trail, if you know what your are looking for(if you have hung cameras and you know where you would put them you can spot a camera a long ways away).
That my take on how they find them. I have steel boxes for mine and I chain them to the tree so far that working to keep them safe.
"I have found if you go the extra mile it's Never crowded".