Yeah, making your cash illegal--it is unless you're willing to explain in year 2032 how you ended up with a 50 gallon drum full of 500 euro notes--will help. But in many countries where the government is corrupt and cannot provide the basic needs, IMO, they need to let the people try to make a living. Social contract: we cannot give you much, but we will not impede you as you try to feed your kids.