“For some people, four walls are three too many.”
Joseph Stalin (1879–1953) General secretary of the Communist Party of the Soviet Union
This seems to have originated with the Spanish military leader Juan Domingo de Monteverde, who, in Francisco de Miranda, a Transatlantic Life in the Age of Revolution (2003) by Karen Racine, p. 239, is quoted as having said: "four walls are three too many for a prison — you only need one for an execution."
Misattributed