Hi Callistemon,
As we said, we understand the concern about other users, and in situations where they are still on the site, you are very welcome to PM them and we are sure that some would welcome that. If users have decided to leave, or have been suspended then that will not be possible, but that is out of our hands. We're afraid we don't think that speculation on someone's whereabouts or why they are not longer around is helpful, or in the spirit of the site, which is why we've deleted certain posts and threads.