Nearly 1,000 social networking sites were up and running on the Internet in 2013, with new startups launching daily-–and billions of registered users. 1 Over 66 percent of the North American population actively uses these sites, integrating them into their everyday practices. 2 These sites represent a vast and varied cultural milieu based on interaction among users and user-generated content. Some social networking sites are commercially owned and charge fees; others allow access by invitation only; most, however, are free of charge and open to new members, although their platforms are licensed, patented, and controlled by privately held corporations.