With more than 1 billion users worldwide, Facebook is the undisputed king of Internet social media. Unlike the early years of social media, however, when Myspace ruled, and Facebook was largely unknown, social networks have now proliferated to a point where they sometimes seem like separate “Internets” unto themselves. Besides Facebook, sites like Twitter, Tumblr, Google+, Pinterest, YouTube, Flickr, Foursquare, Instagram and LinkedIn – to name a few – attract hundreds of millions of visitors and followers. People flood these sites with personal pictures and videos, along with the personal details of their lives. Those details range from the mundane to uncomfortable, inappropriate, salacious, incriminating, sad and embarrassing, insightful and even – or rare occasions – profound. People also use these sites for fundraising, event organizing and political rallies and protests.