What would have added some verve to John Kerry's new biographical ad: As a high-profile activist who crossed the country criticizing the Nixon administration's role in the Vietnam War, John F. Kerry was closely monitored by FBI agents for more than a year, according to intelligence documents reviewed by The Times. In 1971, in the months after the Navy veteran and decorated war hero argued before Congress against continued U.S. involvement in the conflict, the FBI stepped up its infiltration of Vietnam Veterans Against the War, the protest group Kerry helped direct, the files show. The FBI documents indicate that wherever Kerry went, agents and informants were following — including appearances at VVAW-sponsored antiwar events in Washington; Kansas City, Mo.; Oklahoma City; and Urbana, Ill. The FBI recorded the content of his speeches and took photographs of him and fellow activists, and the dispatches were filed to FBI Director J. Edgar Hoover and President Nixon. Every time I read a story like this, I get slightly more sympathetic to the guy.