[NullCharacter]

IIRC, in this case the FBI served up a "diagnostic" executable to users. Since they're using Tor browser, in general, simply enabling Javascript won't do anything to de-anonymize the user (unless the Feds had a TBB 0-day or something of the like). This executable obviously called out to FBI-controlled servers and provided a real IP.

Basically, the only people they ended up busting were people who for some reason decided it was a good idea to download and run an executable being served by their favorite CP site on the "darknet".

[wuliwong]

It seems almost unbelievable but I guess once enough people are offered an executable file, someone will eventually download and run it.