Social networking sites allow users to connect with others and share information online. Some key social networking sites mentioned are Facebook, Twitter, and MySpace. Facebook was founded by Mark Zuckerberg for Harvard students and now has over 800 million active users. Twitter was founded in 2006 by Jack Dorsey and allows users to share brief updates. MySpace was founded in 2003 and was very popular in the mid-2000s but has since declined with the rise of Facebook.