The original dataset is located at [1] (not our HF account). HN data is directly available via the HN API [2]. The privacy policy you point to does not cover HN posts.
> Hacker News Information: If you create a Hacker News account (ID and profile), we do not collect any Personal Information unless you choose to provide your email address and/or information in the "about" field (“HN Information”). Your submissions to, and comments you make on, the Hacker News site are not Personal Information and are not "HN Information" as defined in this Privacy Policy.
I'm a little surprised people don't know the ownership story on HN. Didn't it raise questions when they realized they can't delete their posts without mother-may-I'ing the mods?
HN is pretty up-front that when you post here you are providing them content for free to more-or-less consume as they please.
It covers all User Content, which is comments and post titles (I think) at a minimum.