Stepping up efforts to keep sex offenders off MySpace.com, the popular social networking Web site has partnered with an online identity and background verification company to build a U.S. national sex offender database and dedicate staff to checking the database against MySpace profiles.

Sentinel Tech Holding Corp. will build a searchable database containing information on sex offenders in the U.S. who are registered with various federal and state law enforcement agencies. The database, which will be frequently updated, will include details such as name, age, physical appearance and distinguishing features like tattoos and scars.

MySpace staff will monitor the site 24-hours-a-day for sex offenders who are on the list. They'll remove any matching profiles that they find.

MySpace has been lobbying for new legislation that could help it take the program one step further. The company wants a law that requires sex offenders to register their e-mail addresses in a national sex-offender database. The law would stipulate that the use of an unregistered e-mail constitutes a parole or probation violation, forcing offenders back to jail. If such a law is passed, MySpace can more easily identify sex offenders that have profiles on its site, the company said.

MySpace has been criticized for enabling profiles by registered sex offenders. Earlier this year, journalists around the country began cross referencing sex-offender databases with MySpace profiles, finding matches and publicizing their results. MySpace responded by hiring a chief security officer to oversee safety and law enforcement affairs and introduced an advertising campaign to promote online safety.

MySpace still faces some thorny issues. For example, most sex offenders aren't legally forbidden from creating a MySpace page so it's unclear if MySpace will receive some backlash for removing profiles.