Facebook, the world's second-largest social networking Web site, is adding more than 40 new safeguards to protect young users from sexual predators and cyberbullies under an agreement with officials nationwide that was announced Thursday. The measures include banning convicted sex offenders from the site, limiting older users' ability to contact subscribers under 18 and participating in a task force set up in January to find ways to verify users' ages and identities. "The agreement marks another watershed step toward social networking safety, protecting kids from online predators and inappropriate content," said Connecticut Attorney General Richard Blumenthal, who announced the agreement Thursday with his counterparts in other states. Officials from Washington, D.C., and 49 states have signed on. Facebook, which has more than 70 million active users worldwide, already has enacted many of the changes and others are in the works, its officials said Thursday.