The few times I have placed cams on public land, I have used lock boxes and cables. On most of my private land, I don't use anything more than the included straps. But I've also been bitten by being so trusting in the past too. I have had all sorts of trespassing issues caught on camera over the years - one camera was out and out stolen from the middle of a 1x2mile section, a full 3/4mile from the nearest road, and well off of the beaten path. I've had cards pulled from cameras, and have had others where the trespasser formatted the card and reset the camera (dates all wonky). I'm fortunate enough to have never had the trespassers spot all of my cameras, so even the camera which was stolen was still captured in photos on another trail cam. Mixing in a wireless camera here and there is also a nice assurance - I post a little weatherproof/laminated sign above them, "Smile, this trail camera just emailed me your photo." I have pictures and video of trespassers leaning in close to read it, followed by the hilarious, albeit expected response when they realize they've just messed up and there's nothing they can do to stop it.
Lock boxes stop someone from stealing the card, and stop someone from prying/pulling hard enough to break the plastic mounts on the back of the camera. I have seen pictures of trees which were topped to pull a game camera, and have seen photos of cut cables and paddlelocks... If someone wants it, they'll get it.
What's most unfortunate, in my opinion, is the fact most of these thieves and trespassers are either local folks I know, or folks who know my neighboring landowners, and may or may not have permission to hunt on THEIR property. Sharing a few photos and videos of these thieves and trespassers with my neighbors has caused a handful of guys to lose their hunting privileges on my neighbors' properties, and a couple guys have gotten a visit from the sheriff. Kinda funny how my game camera showed back up the next week in the woods after the Sheriff showed the photo from my OTHER camera to the guy who had stolen it, WITH my camera in his hand - and even funnier how it didn't matter when it went to court and he was convicted of criminal trespass and petty larceny. Another of my game cameras was stolen from my father-in-law's property, a wireless model, Verizon helped me triangulate it - we knew the neighbor kids across the creek had taken it - I knocked on their door and asked if they had seen it, saying maybe a deer had rubbed it loose and maybe a coon had carried it away (holding on my phone pictures of their son and his cousin stealing it which had been emailed to me as it happened). They'd turned the camera off, but Verizon could track it to their house as the last triangulated position. Of course the kids played dumb, but the next day the I started getting pictures from the camera again - they had hung it back up a couple trees over from where it originally was - of course, I received pictures of them putting it back. Wanting to be sure his dad knew the whole story, I did show him the pictures of the kid stealing it, AND putting it back. Can't say the results were very easy for the kid, even after having put it back to save his own hide. Just sad how some folks act when they're in the woods and think nobody will ever be able to figure them out, and silly how they'll act when they're cornered after being caught red handed.
A buddy of mine sticks a product like Tile inside the housing of his cameras (might even be Tile?), so if anyone steals it, as soon as they get near a wifi network, it pings its location for him to retrieve it. It works even without the camera being powered on.
I usually have multiple cameras in an area, and usually one has a view of a few others, so I make sure that one is wireless, in a box, and well cabled in place, on a damned big tree.
