Now that the Mannequin Challenge seems to have run its course, it's time for 'The Backpack Challenge.' That's where a person runs between two rows of people who throw their backpacks at them full-force. Now this is nothing new...kids have been doing this since backpacks were invented, but now its got an official name, and video evidence to go along with it. I see unnecessary injuries and trips to the ER in parents future.