There is always potential danger in technology and there will always be those who use it for sinister purposes but it doesnt mean we shouldnt create it. Virtual worlds would have to police themselves because Im not so sure that everyone having personal accountability and responsibility will ever happen. However I do agree that people will most likely make the virtual worlds their primary residence and exit them to nourish themselves in the real world. Essentially they could live in an apartment full of apartments the size of walk in closets and pay the rent with money they would make in the virtual world.