Most people don’t use the privacy settings to limit access to their Facebook profile. Four out of five simply accept the default setting, which allows their whole network to see the entire profile. In the UCLA network, that’s 50,400 people. The Boston network has 312,404 people. For comparison, the city’s tabloid, the Boston Herald, has a circulation of 201,503. Users may think they’re only sharing with the friends they can see, but they’re actually publishing with the reach of a newspaper.