4) Today, Facebook is the most popular social networking Web site in the world, with over 500 million active users. The site allows users to create personal profiles with information such as their hometowns, work, educational background, favorite things, and religious affiliation. It encourages them to extend their network by adding other users as friends, and many people try to see how many “friends” they can accumulate. To interact with Facebook friends, users can send messages; “poke” each other; upload and view albums, photos, games, and videos; and “tag” or label people in their photos. They can post comments on friends “walls” and create status updates viewable to everyone. In summary, Facebook if fulfilling its mission to “give people the power to share and make the world more open and connected.”