A member of the US Secret Service speaks on a cellphone as US President-elect Donald Trump attends meetings at the US Capitol in Washington, DC, November 10, 2016.

The U.S. Attorney's Office for the Eastern District of Texas has charged 21 people in a money-laundering network that laundered millions of dollars from thousands of U.S. victims.

The charges were made public as a result of an investigation by the U.S. Postal Inspection Service and the Secret Service.

There are more to come." The Secret Service will bring the remaining perpetrators to justice.

Billions of dollars in laundered transactions have been disrupted, along with millions of dollars in cash and cryptocurrencies.

The scheme was designed to target elderly people.

Bill Mack, the Secret Service Resident Agent in Charge, told CNBC's Eamon Javers that the case proves that we can charge these people.

Some of the individuals named in indictments or who had pled guilty were given further information by the U.S. Attorney.

The man was charged in federal court with money-laundering. More than $5 million was laundered from counterfeit pharmaceuticals and controlled substances in the US.

Randall Rule, 71, and Gregory Nysewander, 64, were indicted in federal court for their alleged involvement in wire fraud and mail fraud schemes.

Federal law enforcement has taken actions in the space before.

The federal government claimed that Tornado Cash had been used to laundered more than $7 billion of cryptocurrencies. Dutch law enforcement said that Tornado developer Alexey Pertsev was arrested in Amsterdam after the sanctions.

CNBC's Eamon Javers made a contribution to the report.