The UK's major internet service providers have been ordered to block three websites offering links to pirated material.
Kickass Torrents, H33T and Fenopy – according to the BPI (British Phonographic Industry) – breach copyright on a "significant scale".
The block has been ordered by the High Court and follows a similar ruling last year involving The Pirate Bay.
However, opponents have argued that blocking sites in this way was ineffective and indeed, data seen by the BBC suggests that the Pirate Bay block had only a short-term effect on the level of online piracy activity. Levels of peer-to-peer sharing returned to normal shortly afterwards, the data suggests.
Contrary to that evidence, however, is a recent report from market research firm NPD which indicates that the number of users illegally downloading music has significantly decreased. Fans are now opting for legal options such as streaming site Spotify, it says.
BPI Chief Executive Geoff Taylor says: "The growth of digital music in the UK is held back by a raft of illegal businesses commercially exploiting music online without permission. Blocking illegal sites helps ensure that the legal digital market can grow and labels can continue to sign and develop new talent."
Pirate Party UK offered UK users a way around the Pirate Bay ban. It claims that the BPI is "out of control".
Leader Loz Kay said "The British music industry has nothing positive to show from their site blocks and personal legal threats. Looking at sales figures from 2012, you can't draw the conclusion that stopping access to the Pirate Bay did anything to help artists."
Kaye continued "The UK has now handed the power over what we see on the internet to corporate lobbyists."
