The short answer is the G4 summit.
The long answer has stuff about 4th amendment rights and peaceable assembly.
Hope I've helped.
Cuhail

Taser International received several large orders at the end of 2011, among them one from the Chicago Police Department to upgrade its electric stun guns.
Scottsdale-based Taser (Nasdaq: TASR) received an order for 680 of its X2 stun guns and 4,900 cartridges from Chicago Police in the fourth quarter.
Taser’s X2 is a dual-shot stun gun that is close in size and shape to the company’s long-time X26 model. It has proved popular, and Taser has done trade-in offers for departments looking to upgrade.
The company also received an order for 170 X2s from the Lee County, Fla., Sheriff’s Department; 165 of the devices for the Sunrise Police Department in Florida, and another 155 for the Cary, N.C., Police Department. Another city the company declined to name ordered 250 X2s.