New York MySpace, the world's most popular online hangout, plans to put the cyberspace equivalent of a chaperone at the party and to check IDs at the door.
The huge social-networking site promised Monday to take steps to protect youngsters from sexual predators and bullies, including searching for ways to verify users' ages.
Under mounting pressure from law enforcement and parents, MySpace promised to create a task force of industry professionals to watch over its operations, and other social-networking sites will be invited to participate.
"We must keep telling children that they're not just typing into a computer. They're sharing themselves with the world," said North Carolina Attorney General Roy Cooper.
The deal comes as sites such as MySpace and Facebook have grown exponentially in recent years, with teenagers making up a large part of their membership. This has created a new venue for sexual predators who lie about their age to lure young victims and for cyber bullies who send threatening and anonymous messages.
But Monday's announcement was short on specifics about how improvements would be carried out. Skeptics are doubtful that MySpace and similar sites can eliminate the problem because age-verification technology is difficult to implement and predators are good at circumventing restrictions.
Parry Aftab, executive director of Wiredsafety.org, a children's Internet safety group, said the agreement was a good first step but could have unforeseen consequences.
"There's no system that will work for age verification without putting kids at risk," she said. "Age verification requires that you have a database of kids and if you do, that database is available to hackers and anyone who can get into it."
Aftab estimates that 20 percent of teens have met someone online that they had never met in person, and there are numerous examples of sexual abuse arising from MySpace encounters.
On the same day that attorneys general from 49 states announced the MySpace agreement, New York prosecutors announced charges against a couple who allegedly used the site to lure two girls who were under 15 to their home. Authorities say the couple plied the pair with alcohol, engaged in group sex with them and took them to a strip club where the girls had to dance on stage.
Elsewhere, a 15-year-old girl from Texas was allegedly lured to a meeting, drugged and assaulted in 2006 by an adult MySpace user. In another case, a man got 14 years in prison for using MySpace to set up a sexual encounter with an 11-year-old Connecticut girl. A 16-year-old New York girl ran away to Puerto Rico with a man she met on MySpace.
A 13-year-old girl in Missouri hanged herself in 2006 after receiving mean messages on MySpace from a person she thought was another teen, but it later turned out that the messages were all a hoax.
The only state not joining the agreement was Texas, where the attorney general said he cannot support the effort unless it takes action to verify people's ages.
"We do not believe that MySpace.com - or any other social-networking site - can adequately protect minors" without an age-verification system, Texas Attorney General Greg Abbott said. "We are concerned that our signing the joint statement would be misperceived as an endorsement of the inadequate safety measures."