Stores that sell marijuana — both “medically” and recreationally — will no longer be able to accept MasterCard, according to news reports last week.

Despite state legislation to the contrary, marijuana is illegal under federal law, and banks generally do not engage in business with marijuana companies as a result. That reportedly prompted MasterCard to stop processing credit card transactions for marijuana sales around the country.

An in-depth article at USA Today recently showed once again how drug cartels and criminal syndicates continue to flourish in states where marijuana is legal, and Psychology Today recently reported that, “Highly concentrated marijuana products are causing cannabis-induced psychosis, paranoia, and confusion.”

All of this underscores what we have said for years: Marijuana may be many things, but “harmless” simply is not one of them.