Danger of metals-importing and airliners (was Some of the problems of Habitats)

--- In spacesettlers 18, Darren Brown wrote:
> mining metal from asteroids, while a positive from the
> point of view of the Earth-side environment, has the
> downside that you are basically asking somebody to
> stand under a falling rock, all you need is a simple
> mistake or hostile intent and instead of a
> city/town/landing zone you have a large/hot hole in
> the ground. Ask any military type you want if they
> would rather be holding the high ground or not. When
> dropping heavy rock on people they really must trust
> you, this usually means they and you are on the same
> side/country/company, you get the idea.

Allowing NEO-metals imports to Earth is essentially the same as
allowing airliners to fly. An airliner is essentially a half-million
pound cruise missile -- and it does hold the high ground when in the
air.