I used to think that involuntary account destruction or deletion was a drastic penalty that was issued only to users whose only contributions were spam or offensive content.
I just recently encountered a non-new user (with an established profile with over 100 rep on one of our sites) join another site and immediately post red-flaggable content. I flagged the content and the offending post was deleted, but the user's brand-new account on that site was also deleted, while their other network accounts (including the one with previous constructive contributions) were untouched.
What are the rules on when a moderator should summarily shred a user's account when that user has constructive contributions elsewhere on the network? More generally, if an established user joins a new network site, are they in serious danger of having their account deleted for failure to understand the social context in which they are participating or is deletion reserved for people with no desire whatsoever to contribute constructively - drive-by spammers, trolls, etc.?