Even before the US Congress passed the Higher Education Opportunity Act (see sections 488(a)(i)(P); 493(a)(29)), a number of American universities had adopted systems to prevent illicit file-sharing. Filtering technology company Audible Magic has installed its Copysense appliances at several institutions as part of an automated Graduated Response system.

The Audible Magic system employs fingerprint technology to detect attempts to share copyright-protected files and apply pre-arranged sanctions, often using a browser redirect. Institutions which have adopted these systems report high effectiveness. However, fingerprinting is only one method of identifying content as it passes across the ISP’s network, albeit the most targeted.

ISPs are exploiting Deep Packet Inspection for their own commercial purposes – see, for example, UK ISP Plus Net’s traffic management policy. In the case of ISPs applying such policies, there is a common interest with content providers to prevent pirated video from competing with licensed content.

Site blocking technology has been in use for several years, notably by ISPs who are members of the UK’s Internet Watch Foundation.  BT’s CleanFeed technology is a well-known example of a hybrid blocking system. This compares requested IP addresses with a blacklist and routes suspect traffic to a proxy server. This checks for specific URLs against a blacklist, blocking matching URLs. An explanation of the system is given in Failures in a Hybrid Content Blocking System (R. Clayton, University of Cambridge, 2005).

In August 2011, OFCOM issued a report on the effectiveness of site blocking. It provides a valuable explanation of site-blocking methodologies. On 13 August 2012, Ofcom published a study by CSMG into the extent to which web sites share IP addresses, which bears on the practicalities of site-blocking. Notwithstanding OFCOM’s negative report on the viability of site blocking, the English courts continue to issue site-blocking orders under section 97A of the Copyright, Designs and Patents Act 1988 and the general powers of the court, in 2014 extending the jurisdiction to the blocking of sites distributing goods that infringe registered trade marks.

The technical aspects of sending and handling notices for the purposes of the Graduated Response are set out in the various specifications of the Automated Content Notice System (ACNS), first developed in 2003 and administered by MovieLabs. ACNS includes specifications for sending and responding to automated notices of infringement.