http://www.buzzfeed.com/ries/420-pm-...oulder-quad-6y
A large celebration is held every year on the University of Colorado's Boulder campus, with attendance reaching more than 10,000 in 2008. It has been estimated that in 2009 the crowd surpassed the 10,000 attendee mark that was set in 2008. This would make CU Boulder's celebration of the hopeful legalization of marijuana one of the largest such celebrations in the United States.[4][10] University police have tried various methods to prevent the gathering, including photographing students participating in the event,[11] but the crowd has grown every year.[10] The university and police have taken a more hands-off approach since 2006, emphasizing event safety over possession citations. Recent growth of the medical marijuana industry in Colorado is expected to add momentum to future events.[12]
On April 15, 2009, the Office of the Chancellor sent an e-mail to all CU students regarding the 2009 celebration of 4/20 stating that the event would debase "the reputation of your university and degree." The CU student newspaper disagreed with the Chancellor's analysis.[13]
No possession tickets were issued at the 2009 event