The move comes after the state found at least 269 convicted New Jersey sex offenders registered on the popular Internet social networking site MySpace.com, which has found 29,000 total profiles created by convicted sex offenders.
"MySpace's identification of such a large number of registered sex offenders on its site underscores the need for awareness and action by all networking sites," Milgram said.
Milgram said she expected that MySpace users had profiles on other social networking sites. She expressed concern sex offenders who had profiles removed by MySpace switched to other Internet sites.
The Attorney General's Office has issued three subpoenas to MySpace, but the 12 other sites will be getting letters from Milgram asking for help.
"Together we can make the Internet safer from the dangers posed by sexual predators who may use social networking sites to search for and contact potential victims," Milgram said.
She said the state would help the Web sites in their review by providing them with information about New Jersey residents convicted of sex offenses, but she also noted information about convicted sex offenders is publicly available through New Jersey's online sex offender registry.
Of the 269 convicted New Jersey sex offenders with Myspace profiles, 109 are either on probation or parole. The parole board has charged one individual who appeared on the list of MySpace users with a parole violation related to Internet use, the Attorney General's office said.
Information provided by MySpace included names, e-mail addresses and IP addresses of convicted sex offenders who had registered with state authorities, but state officials said they don't yet know whether they had been in contact with minors.
The first 141 convicted New Jersey sex offenders identified by MySpace logged onto the networking 34,000 times during the time they were registered, which ranged from a few months to two years. Many individuals logged onto the site hundreds of times.
Gov. Jon S. Corzine wants teachers and administrators in all New Jersey schools trained this fall on Internet safety.