Not even apples and oranges. I know that they can still fly safely with only two motors if they are opposing. They may be so safe that it won't be for years to come but eventually after enough mad mothers are up in arms about somebody losing an eye or it getting sucked into an airliner jet that they're going to start heaping on the restrictions. One of the concerns with using them for deliveries at least in a city like Los Angeles is that people will try and shoot them down.

Already been introduced(bad term)? So 1 in 3 households have a drone in the U.S.? OK 1 in 4? You can always count on this statistic- 1 in 10? Nah? Surely 5% of Americans own or use the services of a drone then right? Yeah then they haven't been introduced yet