In 1906 he joined the anarchist movement, having taken part in the 1897 anti-German riots in Prague as a schoolboy. He gave regular lectures to groups of proletarian workers and, in 1907, became the editor of the anarchist journal Komuna. As an anarchist in the Austro-Hungarian Empire, his movements were closely monitored by the police and he was arrested and imprisoned on a regular basis; his offenses include numerous cases of vandalism and at least one case of assaulting a police officer, for which he spent a month in prison. He satirised the lengths to which the Austro-Hungarian police would go to entrap suspected political subversives in the opening chapters of The Good Soldier Švejk.