UPDATE: The feds also seized a station called Big City FM.

A federal judge has given federal authorities permission to seize all the equipment belonging to B87 FM, an unlicensed music station operating at 87.7 FM out of an abandoned theater at 616-624 Blue Hill Ave. now owned by the New Fellowship Baptist Church of Dorchester.

The FCC began investigating the station on a complaint from a Cambridge resident, according to a warrant request filed earlier this month in US District Court in Boston and made public today. Unlicensed stations are allowed to broadcast at the frequency, but only at a very low power - which the station was exceeding by up to 48,000 times, according to test equipment run by FCC engineers.

According to the warrant request, from the US Attorney's office in Boston, FCC investigators were able to trace a coaxial antenna from the roof, near an AT&T cell-phone antenna into the abandoned theater. But they were unable to fully trace it to a possible station studio because the property manager who had allowed them in said he had to leave for another appointment before they could complete following the cable, and that they would have to leave as well.

The FCC says it sent three demands to shut the station to a woman believed to be its owner, but that she sent one back, undelivered and marked "Receiver did not want, refused delivery."

Over the past couple of decades, the FCC has alternated between ignoring the pirate radio stations that have emerged to serve minority groups ignored by mainstream media and taking aggressive action against them. In 2014, the FCC raided and shut Touch FM, a station that had become so popular that Boston politicians and even police officials made regular appearances on its talk shows.