Attorney General Andrew Cuomo said Thursday he'll sue Tagged.com if it doesn't fix the problem within 5 days.
Tagged.com didn't respond to an e-mail seeking comment.
Cuomo said his office had done a three-month investigation.
Investigators posed as users of the social networking site, reporting abusive users and explicit materials.
Among the material they complained about were photos of children who appeared to be under the age of 5 engaged in sexual activity.
Cuomo says that despite complaints, most of the abusive users remain on the site.