Sens. Joe Lieberman (D-Conn.), Herb Kohl (D-Wis.) and Sam Brownback (R-Kansas) will introduce legislation that would allow the Federal Trade Commission to prosecute companies that market violent materials to children. Lieberman had suggested last fall that he would introduce such a bill, after the FTC issued a report on marketing violent products to kids. The senators made the announcement while releasing a report from the National Institute on Media and the Family showing that videogame makers have taken effective steps to stop marketing violent videogames to children. But Lieberman, Kohl and Brownback said movie studios and music producers as a whole are not doing enough and may need extra prodding from the government.