Greg Brock is a reporter for the New York Times.
Brock worked in the Times' Paris bureau before being transferred to the White House Press Corps, and shortly after breaks the story of former Vice President John Hoynes writing a tell-all book about his time in the Bartlet administration. ("Full Disclosure")
A leak on the International Space Station leaves three astronauts (2 Americans and a Russian) at risk of dying in space. The U.S. claims it's unable to rescue the astronauts; however Brock reports that the U.S. actually can save them by using a secret military space shuttle.
The story sparks a major criminal investigation at the White House to find out who gave him classified information about the military shuttle; whoever revealed the information committed a felony. Brock is sent to prison after refusing to name his source. ("The Mommy Problem")