Hate, Lies and Vigilantes: Serbian ‘Anti-Vaxxer’ Brigade Plays With Fire

He was tall and athletic, with close-cropped hair and a black leather jacket. Back in his twenties, he played professional basketball for clubs in Bosnia and Switzerland until, he says, the crisis hit and the money ran out. Now in his early thirties, he has his own business, cleaning and maintaining the facades of Belgrade's skyscrapers. By day, he swings from a harness above the city and by evening he walks its streets, taking matters into his own hands.

His name is Damnjan Knezevic and he says he is defending Serbia from a migrant crime wave. Footage posted on YouTube last year shows him in action with his friends, approaching small knots of tired, wary looking men in downtown Belgrade. The men are asked where they come from. When they mention places like Afghanistan and Iraq, Knezevic and his friends address them in fluent, accented English. "Spread the word," they say, following a loose script. "Don't mess with our women… if you make trouble, there will be trouble… We will be on these streets every night." The warning is delivered calmly. "We are not police, we are not government. We are the people."

Knezevic's group calls itself the People's Patrols. The crowd that assembled to hear him speak at the Belgrade square last October numbered in the low hundreds. In the digital public square, the audience for his views is likely in the low hundreds of thousands: it overlaps closely with the membership of a public Facebook group, Stop Censorship, or Stop Cenzuri in Serbian, which has some 320,000 members. In a country of around 8 million people of whom an estimated 3 million have Facebook accounts, Stop Censorship is one of the more influential formations of its kind - it can claim one in 10 Serbian Facebook users as a member. 

The group is...