Small World proof: I decided to download the new Swift language manual this morning. It is available for free, of course. But when iTunes opened to the download page, I was greeted with a request for my Apple ID password. OK, it's just a formality, here ya go. OK, now I get a request to verify my 'payment info'. For a 'free' item?! Well, it has been several months since I last got anything from the Store... After all the password entries and inserting the missing pieces, the download went smoothly and fast.
I had Mail open, BTW. Almost immediately, I hear the 'ding' of an in-coming message. Sure enough, it was from Apple reporting that I had made changes to my "Shipping and/or billing address". Uh, no, I added the security PIN to the credit card section (which seems to never be saved), nothing about my address changed.
So, my paranoid mind snaps to attention!
Then I remembered your experience and just deleted the thread.
BTW, now that I changed my Apple ID password to something un-rememberable much less pronounceable, I seem to have more requests for it in non-browser apps! Thank goodness I can access (copy) it from the 1Password mini Menu Bar access.