While thousands of people are gathering in Union Square for a candle-light vigil, NYPD is equipped with Long Range Acoustic Device (LRAD), a 45-pound mega-megaphone which can cause permanent hearing damage. LRAD was developed by American Technology Corp. of San Diego which got a $1.1 million (U.S.) contract from the U.S. Marine Corps. According to Wikipedia, the device was originally intended to be used by American warships to warn incoming vessels of their arrival.

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Long Range Acoustic Device from Wikipedia
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