I Know Where Your Cat Lives is an app that has been developed by a Florida State professor who has gathered pictures from the internet of people's cats and by using the geo tag that is often times present on digital photos, he is then able to make a global map of cats and their homes. This is interesting experiment on just how little privacy we actually have and how something as simple as posting a picture of our cats could allow someone to violate privacy. Follow this link to learn more.
http://www.sciencedaily.com/videos/66cfa6077d54b636d7b910c9e074b847.htm