Really OP? Along with this other vague "how do I make $$$ fast and easy" post just 23 hours ago [1]? C'mon HN, stop upvoting this get rich quick clickbait.
What would be the motivation for acknowledging this? What questions do you have?
Steal their idea?
I know someone making that much on a side project, and as you would expect they are very quiet about it. It's unlikely you're going to get much transparency with this question.
Specifics are definitely unlikely to be shared, but I think it would be "safe" for such people to give out some very vague facts—at least, for example, whether these money-makers are b2c vs. b2b vs. enterprise sales; or product vs. service vs. subscription SaaS. Such data would be useful for figuring out what entire categories of approach just wholesale won't work.
No. And if I were, it would certainly not be a side project any more...
There have been way too many of these posts here lately, IMO. Why?