Trying to get a polite policy discussion going here, so don't read it as an attack.
From time to time people miss the large orange bar and start discussing verboten topics. That is obviously not to be encouraged, but it seems as though there are several different responses. Sometimes there's a moderator growl, sometimes there's redaction, and sometimes the thread is simply deleted without comment or evidence.
Several of the "deleted without notice" threads I feel have had the potential to develop into useful technical discussions. There was one a year or so ago with some discussion of Alpha, and recently one that could have developed into a useful discussion of "things to avoid when mounting IRIX disks on Linux and how to fix them", but it was deleted.
I understand that the moderators get incredibly bored of repeating the same thing over and over again, as I'm in a position where I do that quite a bit personally, but it would seem like growls and redaction might be a better way of dealing with problems while letting conversation develop.