The only problem I can foresee is people being shut out of the blocs that are the most benefitial. It could be financial (they can not afford it) or societal (i.e. discrimination). I am not sure what you could really do for the financial issue since there are different levels of income across the country. Social exclusure can be avoided via regulation but even that can be circumvented. Either way, not all blocs will give equal treatment, and there-in lies the problem.