I found this (related?) poll https://news.ycombinator.com/item?id=7818823
Incidentally, if a banned account is making only good posts, we're happy to unban it. I often look at the recent commenting history of banned accounts in the hope of finding such cases, and users sometimes email us about them (as mirmir mentioned elsewhere in this thread). That's super helpful!
One strange phenomenon is that there are banned accounts that post good comments, but revert to posting bad comments that break the site guidelines as soon as we unban them. Then we ban them again and their comments get good again...go figure. Any large-enough population sample includes a long tail of behaviors.
It would be somewhat ironic, if re-enabling interaction with the community is what's driving them to back to bad behaviour. You know, HN as a bad influence.
Somebody should make a shrine of his lucid and technical posts. And also a book.
Anybody know of such things?