Well isn't this nifty.

via the NY TIMES cityroom blog:

The above video, posted by USLaw.com, captures a confrontation on Saturday between the police and several protesters from the Occupy Wall Street movement.

In slow motion, and with annotation explaining what is happening, the video seems to show a high-ranking member of the New York Police Department spraying a substance — the video says it is Mace or pepper spray — toward several women who were standing behind a wall of orange netting. After the spraying, one woman can be seen dropping to the ground, screaming in apparent pain.

More than 80 people were arrested on Saturday as they marched from the financial district, where many have been encamped for over a week, north toward Union Square.

Another version now has over 200,000 views at YouTube since yesterday.