Tuesday May 15th, 2012 informationliberation.com
Chicago Cops Buy Sound Cannon "To Provide Protesters With Public Safety Messages" (InformationLiberation)
Chicago cops want to make sure they're communicating clear "public safety messages" with the folks congregating to protest the upcoming NATO summit, that's why they've just spent hundreds of thousands of dollars on an LRAD sound cannon.

Via Salon.com:
This week, Occupy Chicago welcomes allies from around the country and the world as they descend on the Windy City to protest the weekend’s NATO summit. The Chicago Police Department is ready: Not only has the city passed strict new protest ordinances, but it’s been stockpiling serious riot gear in anticipation of conflict with the protesters.

According to a report from the Guardian’s Adam Gabbatt, in recent months the Chicago police have spent over $1 million on riot equipment, including purchasing a controversial LRAD (long-range acoustic device) — a sound cannon designed to cause extreme pain to those in its path.

The Chicago Police Department is pitching the LRAD largely as a means to communicate with large crowds:

“This is simply a risk management tool, as the public will receive clear information regarding public safety messages and any orders provided by police,” Chicago Police spokeswoman Melissa Stratton told the Guardian.

However, during its first outing at a U.S. protest, during the G-20 summit in Pittsburgh in 2009, police blasted non-lethal sound waves from the device as a crowd deterrent. Unlike firing tear gas or swinging batons, deploying the LRAD does not create a dramatic media spectacle; indeed, videos from the Pittsburgh protests capture the LRAD emitting little more than a high-pitched siren. Those within the sound cannon’s range, however, have described immense pain and severe headaches and — in some cases — irreversible hearing damage. LRAD Corp., which produces the weapon for the military and domestic policing, said that anyone within 100m of the device’s directed sound path will experience “extreme pain,” according to Gizmodo.
You can see this weapon, er, "public safety communication device," used on protesters in Pittsburgh below. Note, you might want to turn down your speakers.