Obviously, the office in Boston doesn't do much about pirates.
Speaking as someone who has had some contact with the FCC over the years: It's not that they don't want to. The problems with this type of enforcement are several:
--They must do things by the book. Verify that the station is unlicensed, send warning notices, followed by in-person visits, followed by in-rem equipment seizure, followed by arrests and trials. At each step of the way, they must conform to the correct laws and regulations and fully document each step, and in the case of equipment seizure and arrests they must obtain warrants (i.e., convince a judge, who has many other things on his/her plate) and enlist US marshalls. Pirates, of course, don't need to do any of that.
--The FCC's budget is continually being cut by Congress, so the available funds to do the type of enforcement they really should be doing in highly pirate-infested areas are a fraction of what they really need, and the manpower is similarly limited.
--That limited manpower must also continue monitoring and enforcement efforts across all areas in which the FCC has jurisdiction, including (but not limited to) cable TV, common carriers, cell phone systems, two-way radios, licensed broadcasters, etc. They don't have the time to focus on just pirates.
One thing that will get their attention very fast: Immediate danger to lives and property. For example, the pirate who parked his spur-infested transmitter at the upper end of the FM band in Florida, and was spitting interference onto the approach frequency at Miami International Airport, such that incoming flights couldn't hear the ATCs to get their landing clearance. They took that one down in a biiiiiiig hurry.