RTAmerica reported that the New York Police Department blasted their "LRAD" sonic weapon against Occupy Wall Street protesters on Thursday, Nov. 17, the two-month anniversary of the beginning of Occupy Wall Street. From their report:

"Violent arrests are taking place in New York where a huge anti-Wall Street rally is underway. RT's Marina Portnaya reports that hundreds of activists are marching across the city, pledging to occupy streets, bridges, the subway in protest against economic inequality."

From Aug. 30, 2004, from the free103point9 archives:

LRAD: RADIO PLAY FOR RNC PROTESTS
By Capt. Qitn
Aug. 30, 2004
A six-minute mp3 radio play by Capt. Qitn for free103point9 Online Radio revolving around the new sonic cannons that the NYPD is using at the 2004 Republican National protests. PLAY CLIP