Max Goldstein (1898–1924), also known as Coca, was a Romanian revolutionary, variously described as a communist and an anarchist.
Born in Bârlad to a Jewish family, he worked as a clerk for two years. He later moved to Bucharest in 1916, where he became a Communist sympathizer. Sentenced to 10 years in prison, he escaped and fled to Odessa (part of Imperial Russia at the time), returning with money and new instructions. He lost a hand, presumably while doing experiments with explosives, and replaced it with a hook, being known to the police as the "man with the hook".
On 17 November 1920, Max Goldstein attempted to kill the Minister of Internal Affairs, Constantin Argetoianu, who was Romania's most vocal anti-Communist politician. The attempt, however, failed: the bomb placed under Argetoianu's train coach destroyed the empty half of the coach.
On 8 December 1920, Goldstein, with the support Leon Lichtblau and Saul Ozias, organized another politically motivated bombing. Their improvised explosive device, made from an unexploded German 76 mm artillery shell from World War I, and placed in front of the Romanian Senate, killed Minister of Justice Dimitrie Greceanu and two senators (Demetriu Radu and Spirea Gheorghiu), and wounded the president of the Senate, Constantin Coandă. The government alleged that their group did not act alone, and that it would have had among its accomplices Alecu Constantinescu, a leader of the left group of the Socialist Party, which in 1921 split and formed the Romanian Communist Party (under the provisional name of Socialist-Communist Party).