All the recent commercial flights I've had the bags unlocked and was
able to put locks on them at the other end before they went to the
baggage hold. Never a problem with that part. Trouble with the soft
bags is a knife can make short work for an entry/exit hole. All the
damned zippers can also lead to internal access bypassing the locks and
that I think was my problem.
Locking a hard case is preferred to preven both someone taking
something out as well as a guard against someone putting something in.
That was? is? a major problem for pax returning from down south. A
package of coke or some such was put into a bag and it was tracked to
the US where it was cleaned prior to customs.... I wouold hope that
hole has been plugged now. That is still a problem with US tagged autos
going across the border. A stash is hidden someplace in/on the car and
then followed home where it is removed. If the innocent occupants get
popped at the border, they have one helluva time trying to work their
way out of why they were carrying discrete packages. No doubt in my
mind that is going on all the time......