One is the video at the finish line that shows what looks like to be an 'older' runner crumpling to the ground as the explosion happens directly to his left.
So when you spot violence, or bigotry, or intolerance or fear or just garden-variety misogyny, hatred or ignorance, just look it in the eye and think, "The good outnumber you, and we always will.
Seattle man trying to dribble soccer ball to Brazil killed by car
This is why you should dribble with your head up . . .