Cynthia Lowen’s Netizens is about three women whose lives have been profoundly affected by cyber sexual harassment. Making its U.S. premiere at Tribeca Film Festival this week, the documentary details the various forms these crimes take, including cyber-stalking, the posting of non-consensual pornography and character attacks. The latter led Tina, a successful businesswoman and one of Lowen’s subjects, to be rebuffed by potential employers, including J.P. Morgan. Through intimate and often moving testimony, as well as brief interviews with experts, Lowen crafts an absorbing documentary that is part biography and part discourse. She does so in a cinéma vérité style, with a minimal use of music, leaving viewers with the feeling that they are in the same room with her subjects. In the opening scene of Netizens, Carrie Goldberg, a New York City lawyer and another of the three women profiled the documentary, is investigating a rape that was…