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With marijuana proponents chanting behind them, U.S. marshals raid Oaksterdam University in Oakland, Calif., on Monday, April 2, 2012. The facility, one of several that federal agents raided on Monday, teaches people how to grow marijuana. (AP Photo/Noah Berger)

Marijuana crackdown stirs protests

Hundreds of medical marijuana activists gathered on the steps of City Hall Apr. 3 to support California's multi-million dollar cannabis industry, under siege since the federal government launched an aggressive crackdown last fall.