From the video page:
From November 30th-- hundreds of people from Occupy Phoenix and AZ Resist came together for Occupy ALEC, a protest at the annual American Legislation Exchange Council. There, the largely non-violent protest became a bit more volatile when the protesters met with riot police.
Thanks to Mnichols0109, Sebas3440, petekosednar, shutdownalec, and Spiritualution for the footage
The police not only pepper sprayed protesters they destroyed banners being held by the protesters.