For what it's worth, HN is on ICE's list of surveilled sites (which it pays a tech contractor to crawl),

https://www.404media.co/the-200-sites-an-ice-surveillance-co... ("The 200+ Sites an ICE Surveillance Contractor is Monitoring")

https://archive.is/Lldzh

Why not? Anything where user interaction is a primary portion of the site's content is social media. The term "social media" predates algorithmically-driven parasocial feeds, though it does postdate things like BBSes and PHPBB.