[atourgates]

I think there's a pretty low risk of serious damage occurring from this drone colliding with much of anything. This is the model being piloted in the videos: http://www.ritewingrc.com/Zephyr_II_ARF.html

It's basically two pieces of EPS foam with some electronics and a pusher prop. If you were going to be hit in the face by a "drone" - you couldn't really pick a less damaging one.

[king_jester]

If the drone has any significant speed, it will cause serious damage to an individual if hit. If it causes a traffic disruption, the danger then comes from a vehicle that may make a maneuver to avoid getting hit or if a driver loses control after colliding with the drone. It it shatters glass, serious lacerations could occur for pedestrians.

This kind of flying is highly reckless and only an asshole would do this.

[CamperBob2]

Still, not everything has to be a Federal case.

[mindslight]

Don't forget it could also spook the horses, tip over apple carts, cause women and children to faint, and anger the gods.

[ElDiablo666]

My thought was that a kite from a nearby park might fly into the face of a skateboarder causing them to veer into the road forcing a motorcycle to evade and crash into a bus, severing the fuel line and blowing up thirty seven children but leaving the driver unharmed.

[mbrameld]

The environment they were flying in presents several challenges to maintaining a reliable control and video signal while flying. In such a populated area the noise floor is likely to be pretty high to start with. The pilot is using 433mhz for control and 1.3ghz for video, so right off the bat you have an 800mw video transmitter within a wingspan (54"?) of the control receiver. The control radio is only outputting 500mw and is considerably farther away. All the buildings close by make for a multipathing nightmare, but can be mitigated by the use of circularly polarized antennas. There is a lot of DIY involved in building one of these with plenty of opportunities for something to go wrong, they're really just hacked together from consumer-grade wireless security systems.

I hope you can see how these factors make it much more likely control could be lost and make your comparison seem pretty silly.

[jrockway]

How do circularly polarized antennas prevent multipath propagation?

[tlb]

Radio reflection off a flat surface reverses the direction of rotation of a circularly polarized signal. A CP receiving antenna will reject them. A twice-reflected signal will go back to the original direction of rotation, but it is much weaker after two reflections.

[sliverstorm]

It still appears to be moving at freeway speeds or greater, and at 65mph even foam can be dangerous to humans.

It's hard to pin its speed, but watch it move through city blocks in seconds & remember that driving/bicycling/motorcycling always looks slower than real speed in POV videos