Gnu, I understand where you're coming from. I don't adopt the same line of behavior, but I understand you.

As to grocery "member cards", I don't find them a problem at all, at least not at the groceries where I shop. The cards are not attached to me; I did not have to give any information to get the two that I occasionally use, from two chains. Just a matter of asking for the discount card, and "here it is". And they provide a worthwhile discount on many items. I save something like $10 each time I go to the grocery.
No invasion of my privacy.

Dave Oesterreich