Are Retailers Requiring An ID Scan In Order To Purchase Cough Medicine?

I was at a local Target a couple of days ago and witnessed a cashier request that a customer show her an ID. The man complied, and flashed his state identification card. This wasn't enough for her. Next, the cashier asked him to remove his ID from his wallet and give it to her. The customer also complied with this request.

The cashier then proceeded to scan the back of the man's state id. After his id card was scanned, the customer asked the cashier why she had to do this. She replied with uncertainty that she thought that it was because he was purchasing cough medicine, and anything that contains alcohol requires that she requests identification.

At this point, I had about a handful of questions running through my head:
(1) Is this a new law?
(2) If this is a law, is it a state, federal, or city law?
(3) Since when has this been the policy?
(4) After scanning a person's id, what kind of database is the information going to?
(5) What in the Big Brother/1984 heck is going on?

I'm also baffled that someone would so easily relinquish their personal information without knowing the reason for it.

I need answers!