He is a civil rights activist who got fed up with watching sagging pants. To paraphrase what he said (the profanity is my own addition), "After marching with MLK, being shot, beat, and face to face with the Klan...fuck that, I didn't go through all of that just so you can disrespect us by sagging your pants."
The sagging pants which has its roots in prison culture is the worst thing Blacks had ever started in the last 15 years. Hope it stops.