Marc Zwillinger has long been a “technology guy,” he says. It’s an interest that brought him to the U.S. Department of Justice in the late 1990s to prosecute cybercrimes, and that landed him in charge of the information-security practices at two large law firms before he opened up his own shop in 2010.

Zwillinger, managing partner of ZwillGen, counts numerous tech companies among his clients, but he was in the news this week for his work for Yahoo! Inc. On Thursday, the Foreign Intelligence Surveillance Court of Review—a body that review decisions by the Foreign Intelligence Surveillance Court—ordered the release of thousands of pages of previously sealed documents in litigation between Yahoo and the federal government over demands for customer information.