A new type of waiver that has emerged out of last month’s perjury trial of I. Lewis “Scooter” Libby Jr. is gaining momentum as more reporters are subpoenaed to testify in court cases.

“Source waivers” release reporters from a long-standing obligation to protect the identities of, and conversations with, their confidential sources of information. The waivers have been most noticeable in the Libby case, in which several reporters disclosed specific conversations they had with their sources. U.S. v. I. Lewis Libby, No. 1:05cr00394 (D.D.C.).