Media groups have laid the groundwork for another court challenge to broadcast “indecency” restrictions by telling the Federal Communications Commission that a 6 a.m. to midnight ban on raunchy programming is “plainly unreasonable.”The FCC is currently in the process of enforcing a law passed by Congress that limits “indecent” programming on radio and TV stations to midnight to 6 a.m. (The cable industry is not affected by the ban, since cable has never been subjected to the same indecency regs applied to broadcasters.) In comments filed recently at the commission, Action for Childrens Television , the National Assn. of Broadcasters, the Motion Picture Assn. of America and other media groups argued against restricting indecent programming. The media groups noted that appeals courts have twice overturned past attempts by the FCC to limit indecent programming, most recently by rejecting a proposed 24-hour ban on indecency. The FCC is expected to soon issue final guidelines for the midnight-to-6 a.m. indecency regs, at which point the media groups will file suit to block the regulations. The case may end up being decided by the U.S. Supreme Court.