Actually, wealthy people are even better off with the current system where they can hide their wealth in a number of competing low tax regimes in the outskirts of the world. It would actually be funny to see this thing coming true, and then turning to a prime terrorist target. Where would they build their defense missiles, in the basement?

In any case, despite the ridiculousness of the idea, this shows that the current sovereign-state compartmentalization of the earth is no longer the best way to run it and we need worldwide cooperation to both fight tax evasion and allow greater mobility of people and goods. Isolating the rich from the masses is only a good idea in the sense that it ends in an explosive way, like the french and bolshevik revolution.