I would like to add to this - while saying I agree with every point made in the above post - Mastercard, Visa, and US financial regulations provide recourse in the case of unlawful billing. This doesn't just mean "someone stole my card and used it" or "someone charged my card when I told them I couldn't" - you could argue that without plastic (using only cash), at least the latter circumstance wouldn't occur, although theft (of cash) is always a concern. There's also "I bought something and it wasn't what the merchant said it was" and "I bought something that never showed up" (if you are paying with credit), for example.

This is not a reason to eschew cash completely. However, I think when considering the pluses and minuses of currency types, it's important to consider that you are protected using plastic in a way that you are not protected with cash. However, you have the privacy, which I consider extremely important.

I wonder if gov'ts are pushing for cashless societies because it would take a toll on the black market? However then I anticipate the black market would just become a barter system.