It appears as if this video was shot in some country outside the US, so I can't speak to whatever regulations or civil laws may apply there. In this country, both FAA as well as state and municipal authorities would be interested in this. FAA regulates the operation of UAVs, but careless and reckless behavior....and that's what's depicted here....can be prosecuted at the local level.
The individual who shot this video could easily be prosecuted for careless and reckless behavior, endangering the public, etc. It is impossible to tell if the people in the near-miss encounters were all the same person (the pilot), or innocent bystanders. In any case, the person could have been killed. Even if the UAV only weighs a couple of pounds, at speed, it could be a lethal weapon.
As UAVs proliferate, I expect we'll see a lot of legislation. Folks who operate them will have to learn that like firearms, you're responsible for what you hit downrange (except in Maine, where the argument that it looked like a deer is an air-tight, legal defense). I also think there will be laws regarding harassment of people (celebrities, etc) using these things. Society in general has never been good about self-regulation.