A big problem with cryptocurrencies, President Trump said last week, is that they help people evade government controls on their transactions.

"I am not a fan of Bitcoin and other Cryptocurrencies, which are not money, and whose value is highly volatile and based on thin air. Unregulated Crypto Assets can facilitate unlawful behavior, including drug trade and other illegal activity," the tweeter-in-chief complained in a jab that applies just as much to paper money and coins.

Just as politicians seem to unite in fear of people buying and selling things without permission, the rest of us should be brought together in recognizing that what scares governments about cryptocurrencies—and cash—is exactly what's good about the stuff.

And politicians really are awfully united in their disdain for anonymous and unapproved trade. "Facebook has announced a plan for a crypto currency platform which appears to meet the needs of drug dealers, human traffickers, tax evaders, and terrorists," Rep. Brad Sherman (D-Calif.) harrumphed recently in response to Facebook's announcement of the Libra payment system. Libra actually doesn't seem to lend itself to such uses, but Sherman covered himself by calling for all cryptocurrencies to be banned.

Earlier this year, Texas state Rep. Phil Stephenson (R-District 85) proposed stripping digital transactions of their anonymity in a bill that, thankfully, seems to have quickly died. In a rare example of snoopy global amity, French lawmakers fretted almost simultaneously about "[cryptocurrencies built] to ensure complete anonymity."