The recent Cambridge Analytica data leak on #Facebook can dramatically point this out. I just checked to see how this breach or leak effected me and here are my results: " Was My Information Shared? Based on our investigation, you don't appear to have logged into "This Is Your Digital Life" with Facebook before we removed it from our platform in 2015. However, a friend of yours did log in. As a result, the following information was likely shared with "This Is Your Digital Life": Your public profile, Page likes, birthday and current city A small number of people who logged into "This Is Your Digital Life" also shared their own News Feed, timeline, posts and messages which may have included posts and messages from you. They may also have shared your hometown." Although I was careful, this still resulted in quite a bit of my information being shared.As you can see from this, "Choosing your Friends wisely", is important. ...