The Justice Department has announced the successful conclusion of Operation Grayskull, a wide-ranging joint investigation with the FBI that led to the takedown of four dark web platforms dedicated to child sexual abuse material (CSAM).

The operation has already secured 18 convictions across multiple federal jurisdictions, with substantial prison sentences handed down to individuals involved in the distribution and promotion of CSAM, the Post Millennial reported.

One of the most significant sentences was handed down last week, when 52-year-old Thomas Peter Katsampes of Eagan, Minnesota, was sentenced to 250 months in prison, a lifetime of supervised release, and ordered to pay $23,000 in restitution. Katsampes pleaded guilty in February to conspiracy to advertise and distribute child pornography.

Court records reveal that he joined one of the dark web sites in 2022, where he actively promoted and distributed CSAM—including material involving prepubescent children—and later assumed a moderator role, enforcing site rules and instructing others on how to share illegal content, the outlet said, citing DOJ records.

“These offenders thought that they could act without consequences, but they were wrong,” said Acting Assistant Attorney General Matthew R. Galeotti of the DOJ’s Criminal Division. “Thanks to the relentless determination of our prosecutors and law enforcement partners, we have exposed these perpetrators, eliminated their websites, and brought justice to countless victims.”

FBI Director Kash Patel described Operation Grayskull as “one of the most significant strikes ever made against online child exploitation networks.” He also emphasized that anonymity on the dark web does not protect perpetrators from federal law enforcement.

“You cannot hide behind anonymity to harm children,” Patel said, per a DOJ release.

Investigators characterized the dismantled websites as among the most “egregious” child exploitation platforms ever uncovered, with dedicated sections for content involving infants, toddlers, and extreme violence, including sadism and torture.

The sites also offered guidance on evading law enforcement, promoting the use of advanced encryption and anonymization tools. According to an FBI official who spoke with CBS News, the platforms drew over 120,000 users collectively and recorded at least 100,000 visits in a single day.

Members of these networks operated under a structured hierarchy, appointing moderators, conducting staff meetings, and monitoring user contributions. Site administrators enforced strict posting rules for CSAM, banned users who violated policies, and oversaw the maintenance of the platforms’ servers, according to reports.

In addition to Katsampes, eight defendants were prosecuted and sentenced in the Southern District of Florida alone for running one of the largest targeted websites:

• Selwyn David Rosenstein (Boynton Beach, FL) — 28 years
• Matthew Branden Garrell (Raleigh, NC) — 20 years and 10 months
• Robert Preston Boyles (Clarksville, TN) — 23 years and 4 months
• Gregory Malcolm Good (Silver Springs, NV) — 25 years and 10 months
• William Michael Spearman (Madison, AL) — life in prison
• Joseph Addison Martin (Tahuya, WA) — 42 years
• Joseph Robert Stewart (Milton, WA) — 23 years and 9 months
• Keith David McIntosh (Grand Rapids, MI) — 55 years

Several others received prison sentences ranging from nearly six to 14 years.

Two additional individuals linked to the case died before charges could be filed. Arrests were also carried out internationally, with suspects apprehended in the United Kingdom, Netherlands, Italy, Germany, Estonia, Belgium, and South Africa.

Operation Grayskull was spearheaded by the Justice Department’s Child Exploitation and Obscenity Section (CEOS) and the FBI’s Child Exploitation Operational Unit, with assistance from multiple U.S. Attorney’s Offices and international law enforcement partners. The investigation falls under Project Safe Childhood, a DOJ initiative launched in 2006 to combat the online exploitation and abuse of children.

“Let this be a clear warning,” said US Attorney Hayden P. O’Byrne for the Southern District of Florida. “We will relentlessly pursue and prosecute anyone engaged in such atrocities, no matter how they attempt to cover their tracks.”