LISBON — The blogger read the email at about 11 p.m. on a quiet night in September, the time of day when he usually posts his popular musings about soccer in Portugal.

The message was from Google, Inc. In it, the company — or, more specifically, its lawyers — explained to the blogger, a slight man in his mid-30s, that the Portuguese soccer powerhouse S.L. Benfica had requested that Google hand over his personal details because he had published 13 articles containing confidential club information on a Google-owned platform.

The blogger had discovered the information online after it was revealed in a broader leak of Benfica documents, and had posted articles about it on his blog, O Artista do Dia. In doing so, he had unwittingly become a small part of a larger scandal that had become a major embarrassment for the club.

Benfica counts half of Portugal’s 10 million inhabitants as fans. Twice the champion of Europe and a regular in the Champions League, it is the country’s equivalent of the Dallas Cowboys or Manchester United, only more so. And now it wanted revenge.