Part of YouTube’s system for reporting sexualised comments left on children’s videos has not been functioning correctly for more than a year, say volunteer moderators.
They say there could be up to 100,000 predatory accounts leaving indecent comments on videos.
A BBC Trending investigation has discovered a flaw in a tool that enables the public to report abuse.
But YouTube says it reviews the “vast majority” of reports within 24 hours.
Reporter: Elizabeth Cassin
Video journalist: Alex Dackevych