Most of the banners were a stark black-and-white and read, "Torture is Wrong" or "Torture is a Moral Issue." Congregations participating in the month-long campaign include Muslims, Methodists, Presbyterians, Jews, Episcopalians, Lutherans, Quakers and Roman Catholics.

The anti-torture group is lobbying for a congressional investigation of U.S. treatment of suspects and prisoners since the Sept. 11, 2001, terrorist attacks.

Government lawyers who drew up the legal basis for the Bush administration’s use of harsh interrogation methods against terror suspects argued that the president had broad wartime authority that could not be limited by domestic law or international bans on torture.

One government legal memo defined torture, as recognized by U.S. law, as covering "only extreme acts" causing pain similar in intensity to that caused by organ failure or accompanying death. An internal Justice Department investigation is now considering whether such advice was improper.