Internet Service Providers and online platforms like WordPress.com are increasingly facing demands to block access to URLs in different countries. These orders can come as the result of court decisions (in the case of the UK and Turkey), or directly from governmental authorities (in the case of Russia or Georgia) and are usually directed at content that governments find illegal or objectionable.

Before now, there has been no standard error message that is both machine-readable and also explains to visitors the reason that the site is unavailable.

Default messages like the infamous ‘Error 404 – Page not found’ or its close cousin, ‘Error 403 – Forbidden’ strike us as inadequate for situations where sites are unavailable for legal reasons. Enter the Internet Engineering Task Force (IETF). They have approved a new HTTP error status code: Error 451, named after Ray Bradbury’s dystopian novel ‘Fahrenheit 451’. This development comes after 2 years of campaigning by groups…