My first motorcycle had hard bags that locked shut and too the mounting brackets at one time, but not by the time I got it. I never heard of anyone stealing anything out of them, and people were surprised to find that they were removable. And were surprised to find out that the reason so many old BMW's have bungy cords wrapped around the suitcases was to keep the lids from flying open and the bags on the bike while riding. I don't think you've got too much to worry about - I bet most people will think these bags are locked and they can't take them off the bike without attracting too much attention.