UK pirate radio, unlicensed illegal broadcasting, was popular in the 1960s and experienced another surge of interest in the 1980s. There are currently an estimated 150 pirate radio stations in the UK. A large proportion of these pirate radio stations operate in London, with significant clusters in Harlesden and the wider London Borough of Brent, Crystal Palace, Stoke Newington, the London Borough of Southwark, the London Borough of Tower Hamlets and London Borough of Lambeth.