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    CASEY AFFLECK

    Cause: Cow Dehorning

    How He  Got Involved:  The 37-year-old actor, dedicated vegan and animal activist signed on with PETA to raise awareness about the painful dehorning of dairy cows. Affleck narrates a PSA where he details the painful process cows and calves undergo on dairy farms. In 2008, Affleck filmed a vegetarian testimonial for PETA. Watch it here.