To be honest, when somebody is not aware of the intricate and precise relationship between the masses and distances of the Earth, the Sun and the Moon, the importance they play (tides anyone?), how fine tuned these values are, and the effects the slightest variations in these values can have on a biblical scale, that person should not be allowed to talk on the matter.
Furthermore, if ravaging our Planet has taught us anything, is that both mining products and byproducts leave behind extensive pollution, disruption to the surrounding and global ecosystem and is something which is not sustainable in the long term, and that applications that originally required the use of metals, for example, can now be achieved using carbon and nano, and that the future is likely with these materials.
Oh yeah, recycling, anyone?
If he's looking for tritium up there, let's see a working tokamak first - the rest is trivial, Falcon Heavy should be ready by then. Otherwise, think about what effect snatching a piece of the Moon is likely to have on Earth and on a global scale.
