Verizon is arguing that the F.C.C. exceeded its authority, and violated the company's constitutional rights. Verizon filed its suit in the United States Court of Appeals for the District of Columbia Circuit, the same court that in April ruled that the F.C.C. had overstepped itself when it sanctioned Comcast in 2008 for blocking users of its broadband Internet service from BitTorrent, a file-sharing application.