The music industry has typically borne the brunt of online piracy, because the smaller file sizes of songs make them easy to download and share. According to the British Phonographic Industry (BPI), which represents the interests of the UK music industry, online copyright infringement cost the music industry over £200 million in lost revenue in 2009, and the cumulative total losses between 2001 and 2012 are estimated to be £1.2 billion (see BPI, File-sharing FAQs).For a number of years, peer-to-peer (p2p) networks were the main source of file-sharing and piracy.

John Enser, a partner at Olswang in London, notes that "we are beginning to see a move away from p2p networks to things like locker services, such as RapidShare and Zshares websites". These websites, also known as cyber-lockers, enable large files of music and other media to be stored, and users can send and use links to retrieve the content. Cyber-lockers make it more difficult for copyright owners to track down where the infringing files are held.Other developments include pirate websites moving to offshore locations like China, Ukraine or Russia to escape prosecution from Western and European laws.

This phenomenon, known as 'bulletproof hosting' has become a rising trend in recent years, particularly since the successful Swedish prosecution of file-sharing website The Pirate Bay in 2009 (see The Guardian, Internet pirates find 'bulletproof' havens for illegal file sharing, 5 January 2010 and see box, The Pirate Bay case).The movement of pirate websites to foreign jurisdictions cannot easily be tackled through litigation in those countries, so often a more nuanced response is required (see box, International piracy solutions).According to Barry Slotnick, partner at Loeb & Loeb in New York, "we are now seeing a more sophisticated means of infringement taking place, with better-funded file-sharing entities than five years ago. Back then, they were hobbyists and kids who thought this was a cool thing to do. Now you have adults who see infringement as a business model".

Karen Thorland, partner at the Los Angeles office of Loeb & Loeb, agrees and says that "the challenge copyright owners are facing right now is that there is an increasing prevalence of pirate sites of various kinds. New ways to share content are springing up every day".