Although I usually couldn't care less about celebrity gossip, I was very interested to see this article (in the India Times, no less!), TomKat threaten to sue baby store over leaked shopping details.
Basically, these two celebs claim a right of privacy and a violation of their right of publicity because a store they shop at has been blabbing the details of their purchases.
I'm interested in this because back when I was writing one of the early articles about digital certificates, The Essential Role of Trusted Third Parties in Electronic Commerce, 75 Ore. L. Rev. 49 (1996), I had a heck of a time finding relevant law on the subject of the ownership of transaction information, a problem that persisted into the writing of The Death of Privacy?, 52 STAN L. REV. 1461 (2000). I finally concluded that for ordinary transactions, where there was no special duty of confidentiality (e.g. lawyer, doctor) or celebrity with a special right of publicity, the basic rule was that customer and merchant both own the facts and can do what they wish with them.
The right of publicity claim is a narrow one: the shop can't claim endorsement by the celebrity (e.g. by using their images in an ad), but that doesn't amount to a gag order. For example, the shopkeeper can certainly brag to customers so long as s/he doesn't imply or claim an endorsment.
But the privacy claim? Absent either a contractual or legal duty, it's just not there. Maybe it should be, but that will take a change in the law.