Agreed; none of the analogies I've seen are really close. I have a couple of attempts:

Analogy 1: the reporter got a letter from DESE, and noticed that there was confidential information printed on the inside of the envelope.

Analogy 2: the reporter got a letter from DESE, and noticed there was a block of intra-office info (document ID, routing codes, etc) at the bottom, and that contained confidential information.

In either case, the critical thing is that the information was sent to him, just in a form/place people don't normally read.