The Counter Terrorism Internet Referral Unit (CTIRU)
The Counter Terrorism Internet Referral Unit (CTIRU) in the Metropolitan Police hold a ‘filter list’ that contains URL links to terrorist content, which can be provided to organisations, usually through a filtering provider, to enable them to block access to terrorist content on the ‘filter list’.
This police assessed list of unlawful terrorist content online represents content which has been assessed by specialist police caseworkers as breaching UK terrorism legislation. These URLs are referred to the hosting sites to request removal and remain on the CTIRU filter list until such time as they are no longer hosting terrorist content.
Further Information provided by UK Gov:
To find out if your WiFi service filters harmful Terrorist content you can run this simple test. If your WiFi service does not appear to include filters to protect against this type of harmful content please get in touch and we will be able to help or advise you on finding the right solution.