Wonder how does that work... is HN considered a "social media site"? Is reddit?
If at some point I opened a throwaway reddit account to ask about the mole in my anus, does should I report that account? And if I forgot the handle, am i doing fraud omitting it?
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.
Good thing those social media sites haven’t embedded themselves in with the administration and aren’t in a position to execute dragnets for secret accounts of visa applicants.
If the form asks you for all your social-media handles, and you fail to list one, that's visa fraud.