And all it takes is some efforts to crossover that with private non-public information, that’s what OSINT is about anyway, and for that reason you (either you or other HN users) don’t choose to have their full name as the user name, or writing their full email, or anything that can be used by even private investigators to reach you let alone 3 letters agencies.

Edit: To add, the guy who created Silk Road got caught by the FBI only from a gmail email posted on public forum (1)

>In the section of the indictment outlining how the link between Ulbricht and Dread Pirate Roberts was established, Tarbell detailed how an FBI expert codenamed Agent-1 had located an early online mention of Silk Road dating to January 27, 2011, when a user under the handle “Altoid” made a post on a forum for users of magic mushrooms.

>“I came across this website called Silk Road,” wrote Altoid, in a post which linked to the site. “I’m thinking of buying off it… Let me know what you think.”

>Two days later, someone using the handle “Altoid” made a similar post on a forum called Bitcoin Talk, recommending Silk Road and providing a link. “Has anyone seen Silk Road yet? It’s kind of like an anonymous Amazon.com. I don’t think they have heroin on there, but they are selling other stuff,” it read.

(1) https://www.cnn.com/2013/10/04/world/americas/silk-road-ross...

Keep in mind, there is what can be proven in court and there is what they know but have to backtrack actual evidence for.