> Wonder how does that work... is HN considered a "social media site"? Is reddit?

Practically, if you’re posting pro-Hamas content here and the guidelines wind up citing that as something they look for, yes.

> if I forgot the handle, am i doing fraud omitting it?

Fraud typically requires mens rea. Not legal advice. But I don’t think this would count as visa fraud.

That kind of ambiguity is a feature to them, not a bug. It means that every citizen naturalized under these rules will have to ponder what happens if USCIS starts digging into their application with specific intent to find a reason to consider it fraudulent, and self-censor accordingly.