FBI agent threatened to arrest CIA interrogators in 2002.

Thinkprogress:
Last week, the CIA revealed that it had destroyed videotapes of interrogations of two al Qaeda detainees, including logistics chief Abu Zubaydah. Newsweek reports today that methods used in the interrogation of Zubaydah “sparked an internal battle within the U.S. intelligence community” to such an extent that one FBI agent “threatened to arrest the CIA interrogators“:
The videotapes, made in 2002, showed the questioning of two high-level Qaeda detainees, including logistics chief Abu Zubaydah, whose interrogation at a secret cell in Thailand sparked an internal battle within the U.S. intelligence community after FBI agents angrily protested the aggressive methods that were used. In addition to waterboarding, Zubaydah was subjected to sleep deprivation and bombarded with blaring rock music by the Red Hot Chili Peppers. One agent was so offended he threatened to arrest the CIA interrogators, according to two former government officials directly familiar with the dispute.