By Jennifer J. Schulp and Norbert Michel

Modern life is full of sharing mundane information with others. Your cellphone company knows where you’ve been, your home security system knows your visitors, and your bank knows your spending habits.

And it’s often not just your service providers that know. Law enforcement has used many of these treasure troves of information without first obtaining a warrant. This warrantless surveillance — which prompted a recent hearing by the House Committee on the Judiciary — may be novel for technology and media companies, but it is nothing new when it comes to the government’s surveillance of Americans’ financial activity.

The Bank Secrecy Act of 1970 (BSA) requires financial institutions to assist federal agencies in detecting and preventing money laundering and other crimes. It does this in a number of ways, including by enlisting financial institutions to report certain customer activities to the government.