NEW YORK — Federal authorities have charged at least 70 men and one woman in the New York City area as part of a child porn investigation.The five-week operation has targeted people who use computer file-sharing programs to exchange videos and photos of children having sex.Authorities say the defendants include a police officer, a paramedic, a rabbi and a Boy Scout leader.Immigration and Customs Enforcement agents in New York led the investigation. Officials plan to announce the arrests later Wednesday.