Marshall says he did it because of a police incident in Miami this offseason.  He was in a restaurant, gunshots were fired outside the place, and when the police showed up, they asked everyone to exit the restaurant.  They were telling patrons which way to exit, but Marshall says, "I went my own way".  He got surrounded by police and threatened with a taser.  So that's why he's protesting.  He didn't follow a lawful order and got singled out for it, so it's obviously "social injustice". 

---