...As my Dad told me when I was young "Locks only keep honest people honest", He also told me to lock it up, that is what I have done! ...
They also let you know when it's been tampered with. In such a situation, the simple seals that let you know it's been tampered with might also be of use if they're able to get past the lock, but then put the lock back (picked then re-locked.) Are alarms no good?
Of course, I'm just helping you go off topic further.