> then SO handed over the data proving it?

Yes, something like that.

The very first mention of the Silk Road online was from a user named "altoid" on Shroomery – the post is actually still up: https://www.shroomery.org/forums/showflat.php/Number/1386099...

altoid was also the name of the account that had originally posted another question on SO, not the one about sessions, but one about Tor services: https://stackoverflow.com/questions/15445285/how-can-i-conne...

The SO account was later changed from altoid to frosty. The email address used to register the SO account was rossulbricht@gmail.com.

Also when the FBI imaged the Silk Road server, the username was "frosty". There were just so many links going back to him :-/

There have been long articles about the Silk Road and its demise, the Wired ones have a lot of details including what I mentioned above. Part 1 is here: https://www.wired.com/2015/04/silk-road-1/

good stuff, thanks!

Yes, the DOJ subpoenaed Stack Overflow as part of the investigation. It's pretty standard.

Normally the DOJ gets access to all the emails of the target of the investigation, then from there they look through the emails and subpoena any companies that might hold additional information - such as Stack Overflow.

it's a good question, and i could only speculate what sleuthing led them to ask SO for information about that account, but yes, they sent an info request to SO, who complied.