Alamy Facebook is owned by Google, a company that has also come under fire for not removing radical videos quickly
The Henry Jackson Society think tank ran a three month long experiment to test the Google-owned site by reporting alarming material it found on it every week.
At the end of the period, moderators had removed just 47 of a total of 107 Islamist extremist postings that glorified terror acts.
For the Islamist hate videos they did bother to act on, it took them an average of 11 and a half days to take them down.
And just 33 out of 94 far right movies that promoted racial violence spotted by the think tank’s researchers were eventually taken down – and on average, after 13 and a half days.