At least three Minnesota men have been charged with participating in a vast, secretive child pornography internet forum after being swept up in a far-reaching FBI sting considered the biggest hacking investigation in federal law enforcement history.
Justice Department officials say the FBI's Operation Pacifier has helped build cases against roughly 200 people while identifying dozens of abused children and those who exploited them.
But Operation Pacifier has also triggered a series of legal challenges that are stirring constitutional debates over how law enforcement tries to smoke out criminals in the darkest corners of the web.
Federal judges in some states have thrown out evidence on grounds that the FBI shouldn't have been allowed to hack private computers all across the country with a warrant from just one jurisdiction. Others remain concerned that the FBI actually committed a far worse crime — disseminating child porn — while investigating the case.
"There's the stunning issue of the government becoming the country's major purveyor of child pornography for a period of two weeks," said Robert Richman, a Twin Cities attorney who has monitored Pacifier cases across the country since he began representing a local defendant earlier this year.
The sting began last year, when the FBI seized the computer server of a child porn site called Playpen. The site operated on the Tor network, a "dark web" browser where users' activities are more easily obscured than on the regular World Wide Web.
But rather than immediately take down Playpen — which had nearly 215,000 members — the FBI kept it running for two weeks, using malware to discover users' locations.
The resulting constitutional questions are unlikely to be addressed in Minnesota any time soon: The first three men charged here chose to negotiate plea agreements rather than join at least 19 legal challenges around the country.