I am dumbfounded that there are so many of you out there that bring your bikes in stores.
First off, I feel MUCH more comfortable that my bike is safe against theft if it is locked up with a u-lock outside of the store than if I bring it inside the store and leave it unlocked. I had a friend who brought a bike inside a small grocery store to run a very quick errand. By the time she got to the checkout counter, her bike was gone. She never got it back.
I've locked my bikes up approximately, oh let's see, maybe 2,000 times, mostly in relatively high-theft urban areas for performing daily errands, and none of those bikes have been stolen. I would be absolutely paranoid about having my bike stolen if I were to leave it unlocked inside a store, however. Again, I'm dumbfounded by all the posts. SMH.