In a recent Open Neurology Journal article, four University of California at San Diego researchers review the evidence concerning marijuana's medical utility and conclude that its continued classification as a Schedule I drug is "not tenable." But the DEA's classification of marijuana has been destroyed many times in the past. Twenty-four years ago, an administrative law judge, responding to a legal challenge initiated in 1972, recommended that marijuana be taken off Schedule I, calling it "one of the safest therapeutically active substances known to man."