If you had the power to make 1 global law that everyone had to obey without question, (or else live the rest of their life in the sewers or something) what would it be?
If education was free then either one of two things could happen. Either the quality of education dips severely - no money for education means no money to spend on resources for schools etc OR more money is charged on top of existing taxes, etc to cover the costs.
Anyway, I see no inherent problems with mass slaughter of the majority of the worlds population. Oh wait, it might thin the gene pool a little. That's about it.