Sleuthing and privacy

This article tells of a woman who used her own sleuthing skills to track down the youths who vandalized her house and cars. The article focuses on the woman’s tenacity and ingenuity, but another aspect of the story struck me: the local grocery store went through receipts for her, and after locating the likely purchase, they went through their surveillance tapes with the woman to identify the purchasers. The article mentions that the perps made a cash purchase. If they’d paid by credit card, would the store have given her the purchaser’s name?
I find it disturbing that the grocery store management went to these lengths to help a PRIVATE investigation.