Authorities arrest 40, seize more than $3.6 million in gold bars in 1st darknet bust Operation Dark Gold is the first nationwide dark web bust.

It's widely known that the things that happen on the dark web are often illegal -- but in a first, an Immigration and Customs Enforcement (ICE) agency along with law enforcement partners took down 40 "illicit vendors" that were operating on the dark web.

The dark web consists of masked IP addresses and a hidden internet that people don't have access to without a specific way to get there usually through a certain web browser.

ICE's Homeland Security Investigations (HSI) recently announced Operation Dark Gold, which would focus on "taking down darknet" marketplaces and vendors.

“The focus of this operation was not only to take down darknet marketplaces but to target the bad actors," Angel Melendez, HSI-NY special agent in charge, said at a press conference in New York.

“Darknet is founded on a network of criminals that trust each other,” Melendez continued.

According to Melendez, HSI agents posed as money launderers who offered to convert virtual currency into cash. From there they could trace transactions from large-quantity shipments of illicit drugs.

Melendez said the drugs for sale on the dark web are often made by the sellers using materials from China and pill presses, 15 of which were seized as part of the nationwide operation. The pills sold this way included Ecstasy and Xanax.

The windfall was huge after the takedown of these illicit vendors in Operation Dark Gold. The nationwide undercover operation produced more than $20 million dollars in cash and cryptocurrency, including Bitcoin. The Justice Department also seized more than $3.6 million in gold bars.

Additionally, they also uncovered guns including a grenade launcher, 15 pill presses, and narcotics, including more than 24 kilograms of Xanax and synthetic opioids.

Melendez said the operation planted what he called a “seed of doubt” among darknet vendors who should now wonder whether they’re pushing illicit goods and services onto government investigators.

According to the Department of Justice, individuals from Vermont to California were involved in the indictment of the criminals involved in the dark gold operation.

Experts say the darknet is a dangerous place.

“The darknet is ever-changing and increasingly more intricate, making locating and targeting those selling illicit items on this platform more complicated. But in this case, HSI special agents were able to walk amongst those in the cyber underworld to find those vendors who sell highly addictive drugs for a profit,” said Derek Benner, HSI executive associate director, said in a release.

Deputy Attorney General Rod Rosenstein praised the men and women in law enforcement for a job well done.

“Criminals who think that they are safe on the darknet are wrong,” said Rosenstein in a release Tuesday. Authorities, Rosenstein said, can now bring down criminals who are on the dark web.

"We can expose their networks, and we are determined to bring them to justice," he continued.

Homeland Security Investigations is the investigative arm of the Department of Homeland Security and falls under Immigration and Customs Enforcement.

Though the public rarely hears about them, HSI has one of the biggest United States investigative footprints internationally.

HSI is a relatively new agency, according to their website. Formed in 2010 under ICE and it combined parts of Offices of Investigations, Intelligence, and International Affairs.

HSI investigates cyber-crime, human rights violations, financial crimes and transnational gang activity.