"Things are getting a little heavy about 10 blocks from here -- police are reported (widely) to have shown up at a large demonstration manning an LRAD. What's an LRAD? Long-range acoustic device. Military non-lethal technology being tested in Baghdad and Fallujah, and it looks like, right now: NYC.
This is heavy and damaging stuff, that leaves no marks when used on humans. Latest text reports say it's been turned on, pointing west, volume low. You can hear live coverage from Union Square by calling 212 400 7458, option 4."