Joining other cable services, USA Network yesterday filed papers to join Turner Broadcasting Co.’s lawsuit challenging the must-carry and retransmission aspects of cable reregulation legislation.USA’s announcement comes a day after E! Entertainment and QVC threw their weight behind the suit, originally filed on Oct. 5. Turner’s suit maintains that retrans consent–requiring cable operators to negotiate for carriage of local broadcast signals–and must-carry, which requires systems to carry signals of stations that decline to negotiate for fees–violates the First Amendment. E! senior VP of business and legal affairs Christopher Fager said, “In the current environment of channel scarcity, the must-carry provision means millions of viewers may be denied access to E!.” By favoring over-the-air signals, which often duplicate programming, the new law wrecks cable’s promise of diversity, he said. Cable pioneer Bill Daniels has also filed a similar lawsuit challenging the same provisions of the law.