The long hook end threads in & out like any other turnbuckel. As often as not I will usually have to spin a couple. After a few times using you get a feel for correct tension when locking over the handel. These thing are a joy compared to my old turnbukles and chains, especially if needing to adjust for off center. Added bonus is refueling, as my front tiedown crosses over fuel door.
Ive not actually heard of anyone having set stole-but because they are so easily removed (and replacement cost) I'd at least slow em down with locks.