Mark "Mordechai" Levy is a U.S.-based political activist and founder of the militant Jewish Defense Organization (JDO), a breakaway faction of the Jewish Defense League. David Tell of the Weekly Standard wrote that the group is "located at the farthest, shadowy margins of American public life." Levy has also organized a paramilitary training camp located in Upstate New York, named after Revisionist Zionist leader Ze'ev Jabotinsky.
Levy first came to public attention after he was arrested in 1981 in Los Angeles on a charge of firebombing a Nigerian diplomat's car that was parked near the Soviet U.N. Mission. Three days earlier, Levy was arrested after attacking a Latvian, alleged to be a Nazi war criminal, in a courtroom as he was fighting deportation.
By the mid-1980s, Levy had left the Jewish Defense League to form the Jewish Defense Organization. After a bomb at the California offices American Arab Anti-Discrimination Committee killed its West Coast director, Alex Odeh, both the Jewish Defense League and the Jewish Defense Organization came under investigation by the Federal Bureau of Investigation Two weeks earlier, according to the New York Times, The American-Arab Anti-Discrimination Committee's New York office appeared on a list entitled "Enemies of the Jewish People" handed out in Washington, DC by Levy. Levy was quoted in a UPI report denying responsibility for the murder: "We had no hand in this, but this man deserved what he got." Asked about the attacks by the New York Times, Levy said "We aren't claiming credit, but it couldn't happen to better people, more deserving people. They're getting a taste of their own medicine."
Levy was charged with four counts of attempted murder and other charges after he opened fire on late JDL leader Irv Rubin in 1989, hitting an innocent bystander. Rubin was attempting to serve a subpoena on Levy. Levy was acquitted of all charges except one count of felony assault with a deadly weapon, for which he served 18 months of a 4½ year sentence. Levy pleaded guilty in 2000 to unrelated charges that he assaulted a 12-year-old boy in New York State.