Well this could be a great thing is the game woul get a crime update as in locks, alarms, break ins, etc.
Also great synergy with other players ideas, like "writing" where you could craft documents/maps/religious tomes/crafting volumes/recipes/technique books, etc and then players would be able to try and steal those documents. As in the better the building the harder it is to break in (better and more traps and alarms, better locks, etc) and of course the larger the place the more items it could hold more safely reducing the chance for the theif to get his hands on important stuff.
(The idea would be that if someone breaks in he or she couldn't steal everything, but would "roll" for available loot he has a chance of finding depending on the buildings/towns security, his/her own robbery skills and luck)