The storming of Brazil’s democratic institutions this weekend was no spontaneous “accident.”

Conspiratorial plots and appeals for a military coup have been circulating on far-right social media for months, and they predictably intensified after Luiz Inacio Lula da Silva defeated Jair Bolsonaro in the presidential election last October. They sky-rocketed in the days before this weekend’s protests rocked Latin America’s largest country.

Most of the militants who targeted the National Congress, the Supreme Court and the presidential palace simultaneously were menacing amateurs. Like most of the insurrectionists who stormed the U.S. Capitol two years ago, they used the occasion to trash offices and take selfies (including with several police officers who seemed loath to intervene). But make no mistake: This violent assault constitutes the most significant threat to Latin America’s largest democracy since the 1964 coup that ushered in two decades of military dictatorship.