YouTube repeatedly fails to remove jihadist videos within two hours of them being posted because of 'staggering' holes in its monitoring, according to a study. It found that the Google-owned video sharing site missed its target for taking down Islamic State films in one in four cases. Dozens of terrorist propaganda and recruitment videos were left up for more than three days at a time, clocking up tens of thousands of views, according to the three-month study by the Counter Extremism Project (CEP). At the G7 summit in October last year, YouTube joined with Facebook, Twitter and Microsoft in an accord aimed at removing extremist content from their platforms within two hours. But in the first in-depth independent study of IS videos on YouTube, the CEP found this was not happening because of 'inexcusable' holes in the service's monitoring system. Researchers found 229 previously identified terror videos were uploaded 1,348 times and viewed on 163,000 occasions over three months from March 8 to June 8, with 24 per cent left on the site for more than two hours. Computer scientist Dr Hany Farid, from Dartmouth College in the US, who developed a system that stops known child abuse films being uploaded, created a similar program that instantly identifies and removes terror videos.