Mark "Mordechai" Levy is the founder and leader of the JDO, and the only JDO member to receive substantial notice in the press. He spends much of his time promoting the JDO's Camp Jabotinsky, which provides self-defense and gun training for young Jews at a facility in the Catskills. Levy is an avid follower of Vladimir Jabotinsky, after whom the camp is named, and often repeats Jabotinsky's motto: "Better to know how to shoot and not need to, than to need to and not know how."