Federal anti-drug officials announced last week that the latest scientific data shows marijuana has become an increasingly potent and dangerous drug—a claim that has been proven false or exaggerated after other government warnings, according to critics. The Office of National Drug Control Policy on Thursday released the latest analysis from the University of Mississippi’s Potency Monitoring Project that revealed levels of THC (the psychoactive ingredient in marijuana) had reached their highest concentration since the government first began testing marijuana in the late 1970s. Whereas THC levels were recorded at 4% in the early 1980s, marijuana samples analyzed in 2009 showed an average level of 10.1%, with some samples reaching as high as 27.3%.