Ofcom has shut down 22 pirate radio stations in a combined operation with Hackney, Haringey, Tower Hamlets, and Islington boroughs, arresting three people, raiding one studio, and writing angry letters to 20 night clubs whose advertising was funding the broadcasts.
The regulator's last crackdown was in 2005, when it closed the door on 53 illegal broadcasters.
Ofcom claims the pirate stations interfere with air traffic control and fire brigade radios, though with the pirates operating between 94 and 107.4MHz they would seem well clear of the London fire brigade, which uses 80, 149 and 462MHz for its various communications.
Air traffic systems are closer to the FM band (between 108 and 137MHz), so interference is possible, if unlikely.
Wireless Waffle generously suggests the interference comes from commercial stations in Eastern Europe, rather than local pirate stations.
Ofcom conducted a survey of London adults, which found that six out of 10 "were concerned when told that illegal broadcasting can cause interference and disruption to the communication systems used by safety-of-life services".
One has to wonder what the other four were thinking.
Mostly, pirate radio stations interfere with legitimate, licence-paying services and (according to Ofcom), illegal broadcasters often use violence to gain access to the roof-tops they need to site their transmitters.
Apparently, stations are also used to communicate with drug dealers, by playing specific songs to indicate shipments, and to fund the drug trade.
It seems likely this crackdown was motivated by commercial stations seeing their listeners drift off to pirate equivalents.
Most of the stations will be back on the air pretty quickly, and Ofcom's action is unlikely to deter the other 150 stations reckoned to be operating in London at any given moment. ®