Like many U.S. firms that transmit pay-TV programs to home microwave antennas, Premier Communications Network in the San Francisco area has a serious problem. For a monthly fee of $21.95, the company lends the receivers that allow TV sets to pick up its high-frequency, over-the-air signals. But people can buy similar equipment in electronics shops for about $100 to watch the programs free of charge.
In June Premier fought back by hiring Ray Conley, a Des Moines lawyer who specializes in catching airwave pirates. Conley searched for microwave antennas whose style differed...