Small comment: "These people all read Hacker News. But they don't know that. Yet." I parsed this as "each of these people don't know that he or she reads--as

Small comment: "These people all read Hacker News. But they don't know that. Yet." I parsed this as "each of these people don't know that he or she reads--as in will read--Hacker News." It sounded like an endorsement for Hacker News, rather than explaining that these people don't know that the people around them also read HN.