Well, applying for a bunch of credit cards and giving banks all our info - names, addresses, social security numbers and the lot - is sure a funny way of expressing concern over our privacy.
I get the privacy worries, but seriously, I think we often overdo this. Microtargeting aided by big data is currency right now, and its existence is one reason we as consumers enjoy a lot of things at a low or no cost. Why are so many communication, direction, cloud services and other services from companies like Google and Microsoft essentially free to consumers? The availability of data and microtargeting. The same goes for the credit card industry. Big rewards and low to no AFs are partly funded by interest charges and swipe fees, but as competition in that market heats up because of us consumers demanding more for less, they too are going to look to microtargeting for additional revenue.
And I am not entirely heartbroken about that. Each one of us has to determine what is super important to us when it comes to confidentiality, but the fact of the matter is that data on "our" transactions don't belong to us - not exclusively anyway. It belongs also at least in part to the merchant - they obviously know what they are selling us. And because the data doesn't belong exclusively to us and we willingly allow access for a third party (the merchant) to have access to that data, they have the right to share that.
The same right belongs to us, by the way. There are shopping discount apps that allow consumers to get additional cashback on certain items by scanning our grocery receipts and sending it to them. Are we in those cases invading the privacy of the merchants, since the receipt bears the merchants' name, address, and even a barcode? Are we invading a merchant's privacy when we file a price protection claim because of a lower advertised price, and without asking for consent, submit our receipt to a credit card company? I doubt many of us look at it that way when we're the ones benefiting from it.