During the “Dirty Thirties”, at the height of the Great Depression, Buck proposed a minimum wage, unemployment insurance, and a 7 hour workday.
On August 11, 1931, the Communist Party offices in Toronto were raided, and Buck and several of his colleagues were arrested and charged with sedition. Buck was tried in November, convicted and sentenced to hard labour.
He was imprisoned from 1932 to 1934 in Kingston penitentiary where he was the target of an apparent assassination attempt in his cell the night of a prison riot. While Buck was sitting in his cell listening to the melee outside, eight shots were fired into his cell via a window, narrowly missing the prisoner.