Everyone is using the internet for buying and selling: a seemingly limitless marketplace. 
Recently, a company Square, founded by Twitter co-founder Jack Dorsey, created an “app” which allows individuals and small businesses to accept credit cards for transactions simply by using a smart phone or tablet, without the need for contracts or monthly fees. The company charges a simple 2.75% per transaction. Purchasing a velvet painting of Elvis at a garage sale on your credit card could become commonplace. Just think, the lemonade stand on the block could soon be accepting VISA, MasterCard and AMEX. Will cash become contraband?
Contraband are goods which are illegal to possess or trade. For example, you would not show up 
at U.S. Customs smoking a Cuban cigar, carrying a counterfeit Louis Vuitton purse and wearing a rhinoceros horn around your neck. These are obvious examples of contraband. Although cash has always been the preferred method of payment for income-tax purposes for many waitresses, self-employed consultants, construction workers and taxi drivers. Now with the capability to complete transactions through smart phones, there is a chance that cash will become obsolete.
What if someday the only people using cash are those involved in criminal activity. Potentially, the only reason to have cash would be to buy something illegal. If you want to figure out who’s running a large criminal enterprise, there is on old saying that you merely need to “follow the money”; at trial, money is admitted into evidence by prosecutors as circumstantial evidence that a defendant committed a crime. In the not-too-distant future, everyone buying and selling illegal items will not be able to complete a hard-currency transaction. At some point, the buyer will not have cash because he will be accustomed to using his credit card—demanding cash will be unreasonable. The illicit seller will now need to open a bank account and conform with his customers’ expectations. Even now, banks require proof of identity and address to prevent money laundering. A legitimate bank keeps track of these accounts and the volume of transactions which will enable law enforcement to easily “follow the money.”
Cash may very well become contraband. Panhandling will be a lost art.
