Facebook employees can view any profile on the site as well as view which other profiles a user has been visiting.
The site terms and conditions imply that users profiles can be compromised. “Therefore, we cannot and do not guarantee that user content you post on the site will not be viewed by unauthorized persons. We are not responsible for circumvention of any privacy settings or security measures contained on the site.”
An anonymous source told Valleywag that viewing personal profiles is thought of as a perk of the job. The source says that one product manager looked up a users password, logged into her account, and changed the profile picture to a graphic image.
The source writes about the incident describing what happened. “The employee got the password and then met up with his friend who was mad at the girl because she turned down his offer to take her to his prom.”
Facebook has had a solid record of protecting user privacy against outside sources. The company has sent cease and desist orders to a number of sites for publishing student profiles. Facebook blocks other users from seeing what profiles you have been viewing.