Medical marijuana proponents express their opinions with signs as agents converge on Oaksterdam University in downtown Oakland, Calif. on Monday, April 2, 2012, serving several warrants. Agents with Internal Revenue Service, U.S. Drug Enforcement Agency and U.S. Marshals were inside Oaksterdam University on Broadway shortly after 7 a.m. The school, America's first cannabis college, was founded in 2007 to provide training for the cannabis industry. (D. Ross Cameron/Staff)