This question offends me. Every time I hear it. It's insulting and insidious, and here is why.
It comes from the self-checkout machines at Sainsbury's supermarket, if you try to pay without scanning your Nectar card.
The machines at Tesco have a different strategy. They entreat, "Please scan or swipe your Clubcard." There is the same intent, the same insistence, the same assumption that I wish to be a part of their covert market research campaign and have simply forgotten. And this, I don't mind. Because I am part of the system, I do carry both cards, I will willingly surrender my shopping history in exchange for a minuscule (to the point of being imaginary) discount.
But there is a subtle difference between the two. Both of these only ask for my identification in the event that I have not already tendered it. And yet J Sainsbury's have decided to phrase their request in the form of a question. Not "Do you have a Nectar card?" or "Would you like to scan your Nectar card?" but "Have you scanned your Nectar card?"
Have I scanned my Nectar card? You know perfectly well that I have not. If I had, you would not be asking.
I'd much rather use a machine that assumes I am in its club, than a machine that assumes I am not intelligent enough to realise that it is aware of what information I have put into it.
In other news: you kids get off my lawn in my day why I oughtta