FATCA (Foreign Account Tax Compliance Act)

FATCA is the most extraterritorially aggressive financial regulation on this list, forcing foreign banks to report on U.S. citizens' accounts or face a 30% withholding penalty. This law has caused millions of expats to be denied bank accounts abroad, with global financial institutions spending over $8 billion annually on compliance infrastructure—a cost far exceeding the $500 million in revenue it generates, making it even more inefficient than the runner-up on cost-to-benefit ratio.