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Although marijuana is the main target of the war on drugs as measured by arrests, people often assume that it's not the sort of thing you go to prison for. Yet calculations based on recent government data indicate that some 59,300 people, 3.3 percent of the country's incarcerated population, are behind bars for marijuana-related offenses such as cultivation, possession, and sales. Chuck Thomas of the Marijuana Policy Project offers this estimate and shows how he derived it in the June 1999 issue of the Drug Policy Analysis Bulletin, published by the Federation of American Scientists and available at www.fas.org/drugs/issue7.htm.