Internet Watch Foundation

The Internet Watch Foundation (IWF) is a charity and company limited by guarantee set up to remove child abuse material in the UK. It produces a blacklist (Child Abuse Image Content - CAIC list) used by ISPs to censor their services (see, for example, Cleanfeed)[1] and notifies UK police about material hosted in the UK and international agencies about internationally hosted material[2]. They also provide a list of relevant, up to date keywords often used by paedophiles to organisations such as search engines[3] and monitor Usenet for illegal content[4]. Many ISPs are members, some actually apply the feed.


The IWF was founded in 1996 by the Metropolitan Police and the Internet Services Providers’ Association (ISPA) as a result of negotiations to combat the publication of illegal child sexual abuse images on the internet while protecting the ISPs from being accused of publication offences under the Protection of Children Act 1978. The IWF's main activity is the operation of an online "hotline"[5] for the reporting of such images and the publication of a blacklist of images used by ISPs to censor their services.[6]


The IWF’s company has 12 board members, [7] while its charitable structure currently shows 11.[8]

The current Chair is Andrew Puddephatt,[9][10] who also runs Global Partners.

Transparency and accountability

The IWF publishes its polices so they are available to the public.[11] As a private organisation, it is not subject to Freedom of Information requirements.


IWF publishes statistics about the volumes of takedowns and numbers of blocks.

There are currently no statistics about the number of appeals and how many of these are successful.

IWF block list and UK takedowns

Splash pages

IWF recommends, but does not insist, on splash pages.[12]

The splash page has a number of good aspects. For instance:

  • warns users that they may be doing something illegal
  • includes a link to their appeals process in case of error[13]

"Access has been denied by your internet access provider because this page may contain indecent images of children as identified by the Internet Watch Foundation.

Deliberate attempts to access this or related material may result in you committing a criminal offence.

The consequences of accessing such material are likely to be serious. People arrested risk losing their family and friends, access to children (including their own) and their jobs.

Stop it Now! can provide confidential and anonymous help to address concerning internet behaviour. They have helped thousands of people in this situation.

0808 1000 900 | |

If you think this page has been blocked in error please contact <your service provider> or visit the IWF's Content Assessment Appeal Process page."[12]


The IWF issues takedown notices to ISPs and hosts.[14]

“These are immediate alerts we send to UK hosting companies about child sexual abuse images or videos hosted on their services. We also send them for non-photographic child sexual abuse images where these are hosted in the UK and break UK law.”[14]

These are sent to hosting, online file storage and social networking providers in the UK.[14]


Content that is blocked or taken down can be appealed.[15] Appeals involve making a complaint,[16] an internal reassessment by a manager and then:

If the original assessment decision is not reversed and the appellant wishes to continue their appeal then the content is referred to the relevant lead police agency for assessment[15]

After this check, the complaint is routed for final appeal. The person handling the appeals is a former judge.

The content of appeal decisions is not currently published.


The IWF’s procedures are audited biannually. The last audit was in 2017.[17]

Controversies and criticisms


One set of concerns include the potential of any form of censorship to expand. Fpr instance, given that te example of the Virgin Killer album cover falls foul of the regulations then perhaps classical paintings that display naked juveniles could similarly be targeted for blocking.[18].

Other concerns include the effectiveness of the approach and the potential negative side effects, including overblocking effects resulting from the routing of traffic via the ISP's proxy[19][20].

BBC journalist Rory Cellan-Jones relates a conversation with Dr. Richard Clayton, of the University of Cambridge Department of Computer Science:

"if the aim was to stop people coming across these images by accident, then the system was a failure because that didn't happen anyway: 'This material tends to be held on paid-for sites or is held by people who don't publish it to the world because they don't want to get arrested.'"[21]

The blocking system put in place for the IWF list can be used for essentially any purpose. Professor Lilian Edwards says:

"The government now potentially possesses the power to exclude any kind of online content from the UK, without the notice of either the public or the courts... ...It's like knowing that Google Safe Search is on, but not being able to change your settings."[22]


ISPA have raised concerns over the costs of implementing blocking technology for some smaller ISPs[23].


The IWF is not a government body or law enforcement agency but a registered charity.[24]

This raises two potential concerns. Firstly, it would not normally be thought acceptable for a private organisation to determine what is or is not legal, and to make enforcement decisions that could impact on free expression in the manner of a court.

Secondly, it has no special legal right to intentionally view child sexual abuse material. It is normally illegal to view this material, yet it is necessary to do in order to assess it and add it to their blacklist. The IWF operate under a memorandum of understanding between the Association of Chief Police Officers (ACPO) and the Crown Prosecution Service (CPS) in which the CPS agree not to prosecute the IWF.

This memorandum of understanding also applies to IT professionals (e.g. web hosts) and others who may have to come into contact with such images for "legitimate purposes" (e.g. deletion, investigation) not already covered by the defence of "necessity for the purposes of the prevention, detection or investigation of crime, or for the purposes of criminal proceedings" in the Sexual Offences Act 2003.[25]

When challenged about the legality of such an arrangement the Home Office were unable to give an explanation, according the website Expert Reviews.[26]

Problems with Appeals

In the early 2010s the IWF was criticised for lacking any form of appeals process or complaints procedure, and failure to notify a content owner that their content has been blocked (e.g. contacting the hosting company or WHOIS registration details for the website in question). See, for instance, this quote from Wikimedia General Counsel Mike Godwin:

"When we first protested the block, their response was, 'We've now conducted an appeals process on your behalf and you've lost the appeal.' When I asked who exactly represented the Wikimedia Foundation's side in that appeals process, they were silent."[22]

The appeals procedure was revised after this.


Problems in the past have arisen because of the blocking technologies, which are not the responsibility of the IWF. A number of incidents have occurred as a result of the IWF blacklist, including:

  • The famous IWF/Wikipedia incident[27]
  • Technical errors in filter implementation at several ISPs resulted in the entire internet archive being unavailable after one or more URLs within it were added to the IWF blacklist[28]

Complants about blocking errors would not use the classification process, but would go through their general complaints mechanism.

The IWF referred a case of a blog called Girls Scream Aloud to the police as a potential case of rape pornography, but the site owner was acquitted.[29]

Remit Creep

Initially the IWF only dealt with images of child sexual abuse and did not operate a URL blacklist, merely operating as a notice and takedown organisation. The blacklist was first introduced in 2004 to combat material held outside of UK jurisdiction.[22] In 2007 their remit was expanded to include taking reports of "extreme" pornography for takedown, although this was excluded from its blacklist.[30] Its remit was expanded again in 2009 to cover non-photographic images of child sexual abuse.[31]

However, in 2011 material relating to incitement of racial hatred was removed from the IWF's remit and moved to a new reporting website,[32] Report It[33]. Keith Mitchell, former head of LINX, notes that:

"There has been visible mission creep. Various additions to the IWF's remit have occurred, increasingly without consideration of their technical effectiveness or practicality. Most notable has been the introduction of a blacklist."[22]

Nevertheless, the IWF’s remit has shrunk back. Extreme sexual material has also been removed from its remit. Plans to monitor and report sharing of files by torrent have been shelved.

IWF feed

Not all UK ISPs subscribe to the IWF feed. Reasons include dislike of interfering with Internet traffic and the cost of doing so.

See Internet Watch Foundation/Feed

ISPs who do not subscribe

  • A&A (terms and conditions)[18]
  • Zen Internet (report on mailing list by Voxra Andersen: "We're not members, and have no intention of becoming one - we also don't 'shape' traffic in any way, shape or form"). (n.b. while Zen are not listed as an IWF URL list recipient they are listed as a financially contributing member)[34]

External links


  1. IWF Facilitation of the Blocking Initiative | Internet Watch Foundation (IWF)
  2. Removal of Criminal Online Content | Internet Watch Foundation (IWF)
  3. Keywords | Internet Watch Foundation (IWF)
  4. Newsgroups | Internet Watch Foundation (IWF)
  5. [IWF reporting page,
  6. IWF History | Internet Watch Foundation (IWF)
  7. INTERNET WATCH FOUNDATION, Company number 03426366 Companies House
  8. - INTERNET WATCH FOUNDATION, Charity Commission
  9. Companies House filing
  10.,, 30 Nov 2017
  11. IWF policies,
  12. 12.0 12.1 URL Blocking: Good Practice
  13. IWF policies
  14. 14.0 14.1 14.2 Takedown Notices,
  15. 15.0 15.1 Content Appeals Process,
  16. Complaints form,
  17. IWF Independent Inspection Report 2017,
  18. 18.0 18.1 Andrews & Arnold Ltd - News - Censorship
  19. Study: Internet Blocking - Balancing cybercrime responses in democratic societies - prepared for the Open Society Institute
  20. Child Abuse images and Cleanfeeds: Assessing Internet Blocking Systems - T. J. McIntyre, University College Dublin
  21. BBC - Can we block child abuse sites?
  22. 22.0 22.1 22.2 22.3 Wired UK magazine on The Internet Watch Foundation - the hidden censors of your internet (Wired UK)
  23. Vast Majority of Consumer ISPs Employ IWF Blocking List >> Press Releases | The Internet Services Providers Association
  24. Charity Information and Donations | Internet Watch Foundation (IWF)
  25. Memorandum of Understanding Between Crown Prosecution Service (CPS) and the Association of Chief Police Officers (ACPO) concerning Section 46 Sexual Offences Act 2003
  26. Home Office clueless over its own anti-child porn measures | Expert Reviews
  27. Internet Watch Foundation and Wikipedia - Wikipedia, the free encyclopedia
  28. IWF confirms Wayback Machine porn blacklisting * The Register
  29. BBC NEWS | England | Tyne | Man cleared over Girls Aloud blog
  30. Criminal Justice and Immigration Act 2008: Section 63 | Internet Watch Foundation (IWF)
  31. Coroners and Justice Act 2009 | Internet Watch Foundation (IWF)
  32. Incitement to racial hatred removed from IWF’s remit
  33. [ Report It
  34. Current Members | Internet Watch Foundation (IWF)