I, too, am concerned about the chance of PMs being read by admin or anyone else, here or otherwise. The very reason they are called "Private Messages" is because they should be PRIVATE. If, by some wild chance, there is a glitch - I won't call it anything else - in our own admin settings, I feel we should be informed. That applies to any board we may be registered on.
Praying this was a unique incident,
Jan in VA