Digitalis Index Librorum Prohibitorum <https://www.theguardian.com/technology/2016/dec/05/facebook-twitter-google-m...> The tech companies plan to create a shared database of ‘unique digital fingerprints’ that can identify images and videos promoting terrorism Google, Facebook, Twitter and Microsoft have pledged to work together to identify and remove extremist content on their platforms through an information-sharing initiative. The companies are to create a shared database of unique digital fingerprints – known as “hashes” – for images and videos that promote terrorism. This could include recruitment videos or violent terrorist imagery or memes. When one company identifies and removes such a piece of content, the others will be able to use the hash to identify and remove the same piece of content from their own network. “We hope this collaboration will lead to greater efficiency as we continue to enforce our policies to help curb the pressing global issue of terrorist content online,” said the companies in a statement. [...]