At the outset of the Khrushchev Thaw in the mid-1950s USSR poetry became very popular. Writings of a wide variety of poets circulated among Soviet intelligentsia: known, prohibited, repressed writers as well as those young and unknown. A number of samizdat publications carried unofficial poetry, among them the Moscow magazine "Sintaksis" (1959–1960) by writer Alexander Ginzburg, Vladimir Osipov's "Boomerang" (1960), and "Phoenix" (1961), produced by Yuri Galanskov and Alexander Ginzburg. The editors of these magazines were regulars at impromptu public poetry readings between 1958 and 1961 on Mayakovsky Square in Moscow. The gatherings did not last long, for soon the authorities began clamping down on them. In the summer of 1961, several meeting regulars were arrested and charged with "anti-Soviet agitation and propaganda" (Article 70 of the RSFSR Penal Code), putting an end to most of the magazines.