Please read this article:
A Reporter at Large
The Invisible Army
http://www.newyorker.com/reporting/2011/06/06/110606fa_fact_stillman?currentPage=1(snip)
The expansion of private-security contractors in Iraq and Afghanistan is well known. But armed security personnel account for only about sixteen per cent of the over-all contracting force. The vast majority—more than sixty per cent of the total in Iraq—aren’t hired guns but hired hands. These workers, primarily from South Asia and Africa, often live in barbed-wire compounds on U.S. bases, eat at meagre chow halls, and host dance parties featuring Nepalese romance ballads and Ugandan church songs. A large number are employed by fly-by-night subcontractors who are financed by the American taxpayer but who often operate outside the law.
The wars’ foreign workers are known, in military parlance, as “third-country nationals,” or T.C.N.s. Many of them recount having been robbed of wages, injured without compensation, subjected to sexual assault, and held in conditions resembling indentured servitude by their subcontractor bosses. Previously unreleased contractor memos, hundreds of interviews, and government documents I obtained during a yearlong investigation confirm many of these claims and reveal other grounds for concern. Widespread mistreatment even led to a series of food riots in Pentagon subcontractor camps, some involving more than a thousand workers.
(more at link)