I think what's happened here is that the PP admins (Internet Brands) have comprehensively lost control of a particular well known moderator (who is posting under at least two names).
However this has been happening for years at some of the other less known PP forums, where bizzare things like this happened many times.
As I said earlier, the owners also need to consider whether in the long term they want to allow the site to become a forum for self appointed private detectives. Those threads may have helped uncover some dodgy characters (easy to do - aviation is a fertile breeding ground for them) but they have massively tainted the site in the eyes of anyone intelligent and reasonable.
Re my postings, if they all get deleted I don't suppose anybody will care. It is nothing like the huge archive of tech posts which GTE contributed over the years. I run my own
website and the stuff I put real effort into goes on there. In fact, funnily enough, when one forum owner asked to to use my full name I said I will agree only if he does delete all my posts first
He declined, but later they did it anyway so one day I will go back there with a script and clean them all off.