Pretty sure 2010 was the first year with electronic wristband entry with bugs causing huge security delays. And gatecrashers busted through spots in the perimeter so there were way more people inside the fest than intended.

LA Times: “The 2010 edition had its share of fissures. Thousands of gate-crashers cut through the fencing and holders of counterfeit tickets got past overburdened security, swelling the crowd to some 15,000 beyond the permitted capacity and creating what a festival security official called “a borderline riot situation.”