Well, if they’re going to take stuff or destroy stuff, I’ll know pretty quick. 
But for practical purposes a highly competent thief will get in no matter how much you spend on home security hardware.
And if you just want an indicator that you’ve been burgled, any old lock will make the average burglar jimmy a window or cut through the wall with a $3 bread knife, hidden behind your shrubs. (or kick down the door, right!) The poor and disadvantaged folk who do most of the petty thievery won’t usually try to pick your lock.
