WASHINGTON — Wrapping up a series of hearings aimed at increasing regulation online, Congressmen told representatives of social networking sites that they should expect new legislation in the form of a comprehensive anti-porn bill.

After issuing the same warning to representatives from Internet service providers the day before, leaders of the U.S. House Energy and Commerce committee told social networking sites such as MySpace that the time had come for government intervention to protect children from dangerous online predators.

“We're all struggling with how to protect our kids, and we're going to put pressure on operators like you to do that,'' Rep. Greg Walden, R-Ore., said.

The committee heard from representatives of MySpace, Facebook and Xanga.

According to Frank Dannahey, a Connecticut police detective who testified before the committee, predators use social networking sites to find potential victims. Dannahey said that he has investigated 17 cases in his state where underage girls were assaulted by adult men they met on MySpace.

General counsel for Fox Interactive, which owns the Beverly Hills, Calif.-based MySpace, told the committee that the site had added numerous safeguards to protect users under 18.

MySpace now mandates that users over 18 who wish to communicate with minors must either know the email address or the minor’s first and last name, Angus said, adding that the site prohibits minors under the age of 14 from joining. However, Angus said there is no effective way to verify the age of a user.

“I watched my 11-year-old daughter, with the help of her older sister, get on to MySpace and create a profile with a false birth date,” Rep. Diana DeGette, D-Colo., said.

Several committee members said that the coming legislation could mandate that social networking sites raise the minimum age to 16. Legislators also suggested that a “zero tolerance” policy resulting in banishment for users who abuse the rules of social networking sites might be in order.

Xanga co-founder John Hiler told the lawmakers that a rating system for content set up by users and site administrators might be the best way to protect minors online. However, sites such as Xanga would be reluctant to institute rules that would restrict free expression, Hiler said.

“Much like comic books, movies and video games before them, blogs and social networks draw much of their popularity from youth, who feel that the new medium speaks to them,” Hiler said.