Recently I was listening to a pirate broadcast and this user called "TDoA_service" was entering some SDRs and set to the same frequency of the pirate station. Is this something that pirates typically experience from curious ham operators or is this the FCC?
The FCC has had pretty good capability for decades. I'm fairly confident in saying that given the commercial contractors they can access for equipment and software, who also do equipment for the military and "the spooks", that their capabilities probably far exceed the KiwiSDR network at this point.
In case anyone cares what the OP saw: it is a request from another receiver to use the KiwiSDR that he was using for 30 seconds to gather TDOA data.
When you go onto a kiwiSDR receiver's web interface and select the TDOA option, you then get to select receivers to use for TDOA. When you have selected the receivers and press "start" to commence the TDOA run, your computer will initiate a request for 30 seconds of reception on the "remote" receivers you have selected for the TDOA run. During that 30 seconds of collection, you will see "TDOA_service" as one of the users of that "remote" receiver.