Policing content on a site where 400 hours of footage are uploaded every minute isn't easy, and can’t realistically be done by humans. That's why YouTube—along with others, including Facebook—has always been so keen to play up the fact that AI will help it do the job. Now, we’ve a little insight into how that’s going. Speaking to the Guardian, a YouTube spokesperson explained that “over 75 percent of the videos we’ve removed for violent extremism over the past month were taken down before receiving a single human flag.” That’s fairly impressive progress on a very thorny problem, but that extra 25 percent is a pretty large miss-rate, and must’ve taken a whole lot of human hours to sniff out. In other words: there’ still a ways to go.