Samuel L. Jackson is calling on celebs who participated in the Ice Bucket Challenge to take part in another movement. The actor recently posted a video on his personal Facebook page asking stars who got drenched to raise awareness for amyotrophic lateral sclerosis, or ALS, to raise their voices for another cause. Jackson said, “All you celebrities out there who poured ice water on your head, I challenge you to do something else. I challenge all of you to sing the ‘We Ain’t Gonna Stop till People are Free’ song.”
