There's been some interesting research done into illegal radio in the UK by Ofcom, which has turned up some fascinating facts:
Almost two-thirds (64%) of all UK radio listeners turn off their radios or switch to a different station when they encounter interference. Some 2% of listeners who experience radio interference say they complain about it. This figure increases to 8% when listeners believe the interference is caused by illegal broadcasters.
The research found that six out of ten London adults surveyed were concerned when told that illegal broadcasting can cause interference and disruption to the communication systems used by safety-of-life services.
In other words, if our maths are accurate and the survey was truly representative, that just over 200,000 people have been upset enough about interference from pirates to have complained about it, or about a third of one per cent of the UK population.
So, we're not really talking about a major problem, then.
Naturally, if you say to people "did you know people playing crunk can knock out ambulance broadcasts", they're going to be alarmed. But we can't actually find that bit in the published research - we can find a figure which suggests that when separated into age stratas, not two-thirds of 65+ respondents were seriously or fairly seriously concerned - and the figures fell away for younger listeners.
The level of interference pirates caused to emergency and aviation services is left untouched by the report - some figures on that would have been nice, but at least Ofcom did ask people why they were listening to these stations. The response, effectively, was "you have managed to oversee an official radio market which doesn't match the audience's needs and desires".
Ofcom indentifies three major audience groups for pirates - what they call "urban music scenesters" - young people who don't hear their choice of music on licensed radio; communities who feel that legal radio ignores their interests, news and needs; and people who prefer to listen to radio in languages other than English.
To be fair, there will always be a chunk of the audience who will see radio coming from the top of a tower block in Peckham as being more tuned in than something coming from a studio with a nameplate and official logging, which means that there will always be some form of unlicensed broadcasting. But a lot of the other complaints - that there are entire genres missing from the radio dial, there are languages unserved, and area for which it takes a house fire or arms cache to hear their names on the news - could have been avoided by a slightly more effective approach to handing out community licences and forcing people to stick to their promises, instead of allowing them to flog 'em off to bigger groups and change their formats to chartier, more mainstream stuff.
Ofcom also shares its clean-up rate for pirates: 63 convictions out of 1,085 investigations. Even if you assume all those convictions were individuals from separate cases, that's a conviction-to-investigation of 6%. Not exactly winning the war, are they?