I always have location off but my old coworker used to leave hers on. One day after work we were waiting for the bus she took a picture of some grafitti near the bus stop. A minute later she got a notification from google asking if they could, I can't remember if it was, tag the picture or add the picture on google maps or both for the gas station next to the bus stop. It was fairly creepy, i'd never seen one of those before. She started turning her location off after that.