My intention was not to cause a major problem. I was just caught off guard by the fact that if I'm composing or reading a PM, anyone who wants to can see who the PM is to or from.
Now that I know this, I will bear it in mind in future.
At least by bringing the subject up, other people here who may not have been aware of this feature before are aware of it now.
I guess if I decide to carry on an illicit, torrid affair via the internet, I'd better use regular E-mail instead of PMs.
ScottMate