FILE - In this April 20, 2009, file photo, a large crowd cheers as the time reaches 4:20 p.m. on Hippie Hill in Golden Gate Park in San Francisco. Thursday, April 20, 2017, marks marijuana cultures high holiday, 4/20, when college students gather - at 4:20 p.m. - in clouds of smoke on campus quads and pot shops in legal weed states thank their customers with discounts. (AP Photo/Jeff Chiu, File)