"Torture by proxy." In the intelligence community, the phrase refers to the transfer (rendering) of low-level suspects to other countries with intelligence services whose standards of interrogation are known to be more brutal than the host country (with full knowledge that the suspect may be tortured and the hope that information may be extracted that would not otherwise come to light).

As one intelligence official explained: "We don't kick the s -- out of them. We send them to other countries so they can kick the s -- out of them."
--San Francisco Chronicle
In the United States, a Presidential finding authorizes the CIA to conduct renditions without due process when necessary. Rendition is used in place of extradition, a legal process, when the standard of evidence may be credible but not substantive enough to press legal charges, or where local court systems would likely not cooperate.

The phrase was discovered and repeated by the media in 2003 while reporting on the case of Maher Arar, a Canadian citizen who was detained by U.S. authorities in 2002 and sent to Syria (his country of birth) for a 10 month interrogation.

Sources:
Daniel Byman. "Reject the Abuses, Retain the Tactic." Washington Post. 17 April 2005. <http://www.washingtonpost.com/wp-dyn/articles/A58301-2005Apr16.html> (25 April 2005).
DeNeen L. Brown and Dana Priest. "Deported Terror Suspect Details Torture in Syria." Washington Post. 5 November 2003. <http://www.washingtonpost.com/wp-dyn/articles/A522-2003Nov4.html> (7 January 2004)
Christopher Pyle. "Torture by proxy: How immigration threw a traveler to the wolves." San Francisco Chronicle. 4 January 2004. <http://sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2004/01/04/INGPQ40MET1.DTL> (7 January 2004)