National Harbor, US : The head of the powerful US gun lobby railed against American media Thursday, saying it was biased and lying about the heated debate on regulating weapons. “One of America’s greatest threats is the national news media that fails to provide a level playing field for the truth,” NRA executive vice president Wayne LaPierre told an annual conference of conservatives just outside Washington. Congress failed to pass a hotly contested gun control law last year, despite a series of recent mass shootings that shocked the nation.