Those within pirate radio say they reach out to the community
Pirate radio stations are booming across the UK, but so are police efforts to catch the perpetrators.
Some 707 stations were raided in 2007, with 881 targeted in 2008, and police say they have a 100% conviction rate.
The BBC's Ben Ando says certain songs may provide code for drug deals and some stations publicise illegal raves.
Supreme FM producer Ray Gambeno defended pirate radio: "We reach out to people in the community in a way mainstream radio can't".
There are about 160 UK pirate stations.
The majority are in London, where they are often based in makeshift studios constructed from plywood - with old carpet laid down to aid sound proofing.
Paul Mercer, of radio regulator Ofcom, says pirate stations often play havoc with the life-saving work of ambulance and fire crews.
He said: "Last year we received 41 complaints from the emergency services and on each occasion Ofcom staff were called to take action against those pirate radio stations to remove their interference."
Generally, pirate broadcasters sell advertising and charge DJs a fee to appear on air. They often install antennae illegally on tower blocks.
Richard Southall, of the London and Quadrant Housing Trust, said: "They break down doors, smash windows, break the actual lifts erecting this equipment.
"Intimidating threats are made to people and it makes a lot of residents life hell."
Supreme FM producer Ray Gambeno defended pirate radio, saying: "We reach out to people in the community in a way mainstream radio can't. You get a sense of warmth."
But Ben Ando says pirate radio is no longer about well-meaning amateur enthusiasts giving city youth a voice.