With most social internet services, getting rid of trolls is usually a matter of reporting a post or blocking the offender. But how do you do that in a fast-moving livestream service like Periscope? By asking viewers for help, that's how. Periscope has introduced a moderation system that creates "flash juries" whenever a comment is up for dispute. If someone flags a message as abuse or spam, a few random viewers are asked to vote on whether or not it's a problem. If the majority believes it is, the offender faces a minute-long ban on comments; a repeat offense mutes the person for the rest of the broadcast.