Either it's a strange coincidence or someone spent a lot of time and care creating astroturfing accounts. All are old, have comments and submissions, seem like real people.

They all appear to have suspiciously low karma and durations of consistent activity. I think someone cough went to a lot of trouble..

Are you for real? Look at my account history. You really think I'd spam HN. Been on flights all day or I would have addressed these comments earlier. Suspect these are just happy people. More than willing to address this with HN admins if they have any questions.