Very cool... I had a chance to play with one of the more common four-engined ones last year, this one looks like it has even better performance. We had a gyro-stabilized camera on ours and a head-mounted display for the pilot on the ground... pretty impressive for amateur level stuff.
Of course the usual suspects are building professional ones and hawking them to law enforcement etc., and there are plans and prototypes for models armed with tear gas launchers, rubber bullets and even tasers... what a fun world we live in.
