This shit makes me very angry and sad at the same time. I don't know exactly what the G20 in all about but I'm gonna look into it. Very scary that they are getting away with actions like this. Using an LRAD on people is not something to trivialize. This is from the LRAD manufacturers web site:
The Long Range Acoustic Device™ (LRAD®) is a highly directional acoustic array that is designed for long-range communication and unmistakable warning. The LRAD device can issue a verbal warning and has the capability of following up with a deterrent tone to influence behavior or determine intent.