Those are very nice shots, but... did you considered the local laws before flying them in city centers? From where I am (Spain) it's a big no no to fly one over any even sparsely populated area. It's forbidden (AKA requiring lots of permits) even if you are not flying over people (like in the Thames) or the drone is less than 250g.
Yes, I think it's important to consider and understand the laws wherever you happen to be flying. More importantly, one should fly responsibly regardless of the details of the law. Which is a bit like driving a car, or doing anything really.
In London, you need to have a drone license and be registered as a drone operator. I have both of those. You're meant to ask permission from the port authority to fly over the Thames, but I think more importantly, you're not allowed to fly drones west of Tower Bridge, which is why that video is shot from the east.
I don't think the rules of sensible drone operation are yet (if they ever can be) neatly codified as law, and I have also observed a significant mismatch between what's written and how those rules are enforced. Fortunately, laws written by governments aren't quite as black and white as laws in programming.
