Please don't post like this. If you see a [dead] comment that shouldn't be dead, you should vouch for it (https://news.ycombinator.com/newsfaq.html) or email hn@ycombinator.com so we can fix the problem
I occasionally see comments from users like this one, with all but occasional comments dead. If I look back far enough, sometimes I can find a comment that was transgressive. But often enough, nothing.
So should I be emailing hn@ycombinator.com about those?
"[dead]" means that an account has been administratively banned. "flagged" only shows up per-comment, showing that users have flagged that comment.
Tracking back through history to find the banning offence can take a while. But you can vouch for either individual posts or a user as a whole, by email, as described above. I do this myself on occasion.
Flagged / banned account activity isn't visible unless you've set "showdead" to on, in your HN profile settings.
It's so sad to see banned accounts consistently making interesting and constructive comments, which are mostly all dead, except for the occasional vouched one. And sometimes for years. That's quite the cruel punishment.
Being paranoid by nature, I routinely check my account from other IPs whenever my comments aren't getting replies. And I wonder if others do that. I mean, could someone go for a year without realizing that their account had been banned?