Brookstone Return Policy -- Is this legal in CA?

I was given a pair of memory foam slippers that were purchased this week. I returned the slippers to Brookstone to exchange for a different size. The packaging was intact, slippers had not been worn and I had a gift receipt.

To get an even exchange, the clerk insisted on swiping my drivers license and adding my address to the computer. She then went in the back and made a copy of the receipt. I feel like this is an invasion of privacy and in fact I think I may have been issued a small check from some small claims settlement for something similar. I will definitely think twice before shopping at Brookstone.