Although it is impossible to see who is viewing their Facebook profile, users can see who is following them. Users need not be friends on Facebook with someone in order to follow them and see certain status updates.
The list of followers can be monitored by clicking on the Friends link in the Facebook profile. An option to see followers appears on the next page. Users can block people they do not wish to be followed by or adjust their privacy settings. Some third-party applications may attempt to gather information on users' followers or offer reports on who has viewed their profile. However, these are not legit services.