In countries like Bangladesh the gov does not have the diplomatic resources to use the same tools that NSA offers to the US or any US allies. They employ low-level white hat / grey hat servicemen to do their online digging work. It is the same with many developing and underdeveloped nations.
Besides, I am sure NSA data is accessed in case of national security - NOT detecting / tracking crypto users for political purposes.
You're missing the point. NSA or not NSA, any government agency that is interested in tracking their citizens' involvement in crypto could be doing what LoyceV does and scrape those posts without making an announcement thread here. They could be doing even more, e.g. scrape posts in Investigations.
Information, shared by anyone on this forum is kind of made with the confidence that they can perhaps edit out any unrequired information in the future - hence the existence of the edit button.
You cannot "edit out" anything from the internet. The edit button is useful to fix spelling errors and such. It's utterly useless for hiding information, which could have been copied by anyone, could have ended in Bitcoinalk backups (and yes, likely to be handed over to law enforcement if theymos gets a subpoena), etc.