If you tighten them with a k-wrench, the only ones opening it, have a k-wrench. You can buy one here... K Wrench | AJIK Overland Exchange
Not supposed to tighten with a tool, only loosen. Hand tight only. I run a cable lock through the top loops of the cans, but that doesn't help with sabotage only theft.
I'm more a two days tripper than a rock crawler or a truly overland type so my truck is fine for what I do.