Blocking and categorizing content

We work to block and remove the most explicit photos and videos of child sexual abuse from the Internet.

Access blocking

Preventing users from accessing websites that show child sexual abuse material is an important part of the fight against this crime. By blocking access, it stops re-victimization of the children abused, and has a pedagogic effect on users who may be about to commit a serious offence by viewing or downloading illegal material.

To block access to Internet domains that disseminate child sexual abuse material, police can give Internet Service Providers a list of domains, or web addresses, to block in their networks. When users attempt to view the page, they may be redirected to a ‘stop page’ containing information on the reason for the redirection, links to legislation, where to complain, etc.

Preventing access to child sexual abuse material is used as a complement to investigations, arrests and undercover operations.

It is important to note that no criminal cases are generated as a result of anyone being redirected from a domain containing child sexual abuse material.

Access blocking should be used as part of a holistic approach to combating child sexual exploitation.

The INTERPOL ‘Worst Of’ List

We maintain and provide a list of domains that disseminate the most severe child abuse material worldwide. It is available to national police through our National Central Bureaus.

The “Worst of” list contains domains that distribute child sexual abuse material and which have been verified by at least two different countries/agencies. The domains entered into in the “Worst of” list contain images and movies which fit the following criteria:

  • The children are “real”;
  • The ages of the children depicted are (or appear to be) younger than 13 years;
  • The abuse is considered severe.


The Baseline system allows partners in the public and private sectors to recognize, report and remove known child sexual abuse material from their networks.

They can do this by checking images and videos against INTERPOL’s Baseline list, which contains the ‘digital signatures’ of some of the worst child abuse images and videos.

If a signature matches, network operators alert the police and remove the material, thereby limiting its circulation.

Baseline criteria

To be included in the Baseline list, child abuse images and videos must be recognized as such by our specialist network of investigators, and meet specific criteria in terms of the severity of the image content, for example those believed to feature children aged 13 and under.

The strict criteria ensure that the Baseline list refers only to images and videos which would be considered as illegal in any country.