Tracking the HTTP 451 Error Code
May 15, 2022
Since 2016, the HTTP 451 code has been an adopted standard (just like 404 not found or 500 internal server error) and should be returned when a server denies access to some content as a result of a legal request. This project uses the Censys internet scanning project to automatically perform searches for publicly accessible servers that are providing HTTP access and returning a response code of 451 gather daily statistics, and save copies of the fully HTTP response body.
You can view up-to-date data, visualizations, and additional details about the project at https://http451.info
See this page for more information about the project.