Given the variety of known weaknesses, exploits, categories
of papers, and increasing research efforts against tor and
overlay networks in general, and the large number of these
"mystery gaps" type of articles (some court cases leaving hardly
any other conclusion with fishy case secrecy, dismissals, etc)...
the area of speculative brokeness and parallel construction
seems to deserve serious investigative fact finding project of
global case collation, interview, analysis to better characterize.
Early on August 2 or 3, 2013, some of the users noticed “unknown
Javascript” hidden in websites running on Freedom Hosting. Hours
later, as panicked chatter about the new code began to spread, the
sites all went down simultaneously. The code had attacked a Firefox
vulnerability that could target and unmask Tor users—even those using
it for legal purposes such as visiting Tor Mail—if they failed to
update their software fast enough.
While in control of Freedom Hosting, the agency then used malware that
probably touched thousands of computers. The ACLU criticized the FBI
for indiscriminately using the code like a “grenade.”
The FBI had found a way to break Tor’s anonymity protections, but the
technical details of how it happened remain a mystery.