A system and method uses any or all of information of a user and/or user's activity at a second web site, information of the user's friends or other connections at the second web site, or registration information of the user, to determine whether to allow the user to communicate with other users of a first web site, prevent the user from communicating with other users of the first web site, or monitor the user's communications and allow or prevent the user from further communication based on the monitored communications at the first web site.