Here's how Trump's wall plan could expand the black market

Security and money-laundering experts who watch the underground financial economy say that in all likelihood, such a rule would not stop the remittances: It would simply send them into the underground economy. Couriers or others will help facilitate money transfers across the border; Mexican nationals could also transfer money through a digital currency like Bitcoin."I guarantee you, before the wall has five bricks in it," said [Don Semesky, a former financial investigator at the IRS and DEA], "there would be an informal black market."Either way, the result would be devastating for law enforcement: they’d lose a powerful tool to trace dubious money tied to drug-runners, terrorists, or human traffickers. [Politico]