The popular fast-food joint Shake Shack is opening some outlets in New York City that won't accept cash. Instead, you'll need to order by phone or at a kiosk that takes your credit card.

This is just the latest manifestation of a general business trend according to a recent article in the Fiscal Times. After citing as examples some high-end restaurants and the airlines (which stopped accepting cash in 2010), the Fiscal Times explains the reasoning:

"Businesses claim that not accepting cash reduces the chance of stores being robbed, eliminates the temptation for employees to steal money, eliminates the time needed for workers to travel to and from the bank and even reduces expenses by dispensing with the need for bulky cash registers."

Fair enough, but as the fiscal times points out, there are many people in today's economy who lack access to credit of any kind and who use cash or all transactions. Not accepting cash is basically telling poor people that "we don't want your business."

But there's another issue here that may be important for more than just the credit-less hoi-polloi--people who've concluded that credit cards specifically and the banking system generally is so insecure that keeping all your money there is an unacceptable risk.

As I pointed out in a previous column, the recent cyber-hack of Equifax will make millions of people vulnerable to identity theft... for decades to come. Considering that dozens of corporate and government sites are hacked every year, deciding to put some, most, or even all, of your wealth in cash is no longer an entirely crazy idea.

Going back a little in history, people holding large amounts of cash right before the Great Depression were positioned perfectly to take advantage of the collapse of the banking system.

According to family legend, my grandfather was one of them. He didn't trust banks so he kept his money in greenbacks buried in the root cellar. After the crash, he used that money to buy restaurants. Many decades later, that investment put me through college.

While I've not personally taken the leap, the idea of having a tasty pile of cash squirrelled away in a storage unit or safety deposit box (think Breaking Bad but with legally-gotten gains) isn't entirely unattractive.

(As a complete aside, I've always wanted to buy a new car and pay for it with a cloth bag full of money with a huge dollar sign sewed on it, like that held by Monopoly Man. And, BTW, hooray for Monopoly Man!)

The option to keep your wealth in cash becomes far less viable if more and more businesses, like Shake Shack, stop accepting cash. It's already nearly impossible to pay taxes, for instance, using cash. And paying for an airline ticket with cash is a good way to get "held for questioning."

If cash stops being "legal tender for all debts, public and private" (as it claims on each dollar), then we're all stuck with a system where a company like Equifax can put our entire wealth at risk for decades to come. And that might not be the best of all possible worlds, to say the least.