Hundreds were arrested in the FBI's Operation Pacifier [0], and their cases are still actively working through the courts. We don't hear much about Operation Pacifier, and I assume that's by design.

For security-aware technologists, however, there is an important detail: the feds have some heretofore-undisclosed exploit that is used to de-anonymize Tor users, which gets referred to as "the malware".

They're so interested in keeping the details of this secret that they dropped all charges on one of Operation Pacifier's biggest offenders, because he had a skilled lawyer who convinced the judge that the government would have to disclose more details about how it unmasked him to ensure that his constitutional rights had not been violated.

It's interesting that the tool used gets referred to as "the malware". Is this a real-world use of the Intel ME or just your run-of-the-mill trojan? Is there a backdoor in the Tor Browser Bundle, and that's why the government still allows such easy access to it? Is the claim of "malware" just a diversion to prevent people from learning that they have a crack for the Tor network itself? Dunno. Would be interesting to find out though.

[0] https://en.wikipedia.org/wiki/Operation_Pacifier