I was in Montreal last month, walking the streets recording, with a digital camera, the various appealing menus just to show my wife what was available to eat since she wasn't with me. I had no problem for several hours, until a guy ran after me after I had photographed his window, which had his viands listed. He said it was ok to photograph, but he wanted me to ask first, and after a very low key discussion, told me that it is illegal to photograph storefronts! Well, of course this is baloney. What's the difference between your storefront and Notre Dame Cathedral's store front? The only difference is that it's yours, and you are paranoid.
Believe me, the last thing I want is a confrontation that can produce nothing but bad feelings, so I didn't say what I just wrote above. Instead, I just asked him whether he would like me to erase the image. "No, it's not whether you erase the image or not, it's just that you can't take pictures without asking". I'm not here to correct each and every person's misguided opinions, so I just left. Sure, he ought to know, but so should hundreds of thousands of others.