A massive international operation targeting dark web markets culminated in 288 arrests, the seizure of 1,875 pounds of drugs and more than $50 million in cash and cryptocurrency, authorities said Tuesday.

Operation SpecTor was coordinated by the FBI and Europol, spanned nine countries and dozens of law enforcement agencies, and is believed to have met its goal of significantly disrupting fentanyl and opioid trafficking on the dark web.

The operation uncovered vast networks of manufacturers, online supply chains, buyers, re-sellers, and users. It also provided further evidence that the dark web provides criminals with only a veneer of anonymity.

SpecTor began in late 2021, led by the Department of Justice’s Joint Criminal and Opioid Darknet Enforcement (JCODE) team. JCODE was set up in 2018 to coordinate complex, multi-agency investigations into virtual marketplaces selling dangerous and illegal drugs around the globe.

In a report, the FBI said JCODE’s approach to investigations is two-pronged.

Operation SpecTor spanned three continents, seized millions of dollars, and removed tens of thousands of potentially lethal drugs from circulation.

“Teams target the infrastructure of the darknet marketplaces to ultimately take them offline. They then analyze the data, including usernames and accounts, to develop leads they can send to partner agencies around the world to build out investigations.”

In this case the target was Monopoly Market, a dark web market set up in 2019 where drugs were sold worldwide for cryptocurrency. Its take-down by German authorities in December 2021 marked the completion of one phase of Operation SpecTor.

Europol said Tuesday the seizure of Monopoly Market’s criminal infrastructure provided “troves of evidence” authorities used to compile “intelligence packages” for investigators to pursue.

“These target packages, created by cross-matching and analyzing the collected data and evidence, served as the basis for hundreds of national investigations. The vendors arrested as a result of the police action against Monopoly Market were also active on other illicit marketplaces, further impeding the trade of drugs and illicit goods on the dark web.”

In one operation in the U.S. last fall, investigators found six pill presses; 10 weapons; bundles of cash; and approximately 450 pounds of illegal drugs, which included thousands of pills, powdered fentanyl, marijuana, mushrooms, heroin, and other substances in a California basement. (Image credit: FBI)

The 288 vendors and buyers arrested in the operation “engaged in tens of thousands of sales of illicit goods” across Europe, Brazil and the U.S., where 153 of the arrests were made.

“This represents the most funds seized and the highest number of arrests in any coordinated international action led by the Justice Department against drug traffickers on the dark web,” Attorney General Merrick Garland said.

The operation resulted in over 100 U.S. federal operations and prosecutions.

In one case, a 29-year-old Florida man was charged with distributing fentanyl, methamphetamine, and heroin through dark web markets and the U.S. mail. After his arrest, investigators found a list of 6,000 customers he had supplied. He was sentenced in December to 16 years in prison.

More arrests could follow, with Europol noting: “As law enforcement authorities gained access to the vendors’ extensive buyer lists, thousands of customers across the globe are now at risk of prosecution as well.”

Earlier this year the DoJ led a coordinated international operation that brought down Genesis Market, the largest dark web marketplace for stolen credentials.

Last year, together with German authorities, the DoJ seized Hydra Market, the world’s largest and longest-running illegal marketplace.