Now armed with blockchain forensics instead of briefcases of cash, the U.S. Secret Service is quietly becoming one of the most sophisticated crypto crime-fighting units in the world.

According to Bloomberg, its Global Investigative Operations Center has seized nearly $400 million in digital assets—stored in a single cold wallet—through operations targeting scams, fraud, and extortion.

One recent case illustrates the agency’s evolving reach: after a teenager was sextorted for $600, agents traced the crypto through a money mule to a Nigerian national allegedly responsible for thousands of illicit transactions.

The agency, led by investigative analyst Jamie Lam, specializes in digital financial crimes using…