[rsheridan6]

The whole thing shouldn't weigh very much, assuming it's limited to delivering lightweight objects, and the rotors could be covered with a screen. I don't see much potential for danger. The worst thing that could happen would be a total system failure causing it to drop out of the sky, and even that could probably be mitigated with something like a failsafe that deploys a parachute if the speed is too high.

It should be safer than multi-ton delivery trucks, which can and have killed people. I was a mailman at one time - we were required to get out and look behind the truck before backing up because a mailman once killed a toddler who wandered behind his truck (though I doubt very many carriers actually follow that rule).