I'm with the others. They're far more likely to just steal the whole rig, and that's easily done by a heavy wrecker with a wheel lift, a cordless impact wrench, and a short ratchet strap. Lift the front with the wrecker, and while one guy is strapping the wheels down the other slides under the truck and braap-braap-braap-braap, off comes your driveshaft. Rickety-rack-rickety-rack, your driveshaft is strapped to the frame rail, both guys are in the truck and it's GONE.
That's standard operating procedure for a tow truck driver, so unless you're there screaming your fool head off, nobody will be the wiser. They'll probably have the yellow lights flashing, be wearing reflective vests and hard hats, so they look official, like they belong there. Again, unless you're standing there screaming your fool head off, everybody will assume it's a routine tow.
The standard locks are enough to prevent the typical thief, who is only looking for something easily removed to sell as scrap.
