It was the emergence of photos from Iraq's Abu Ghraib prison in April which first alerted the world to the fact that there were US soldiers abusing those in their charge.
The photographs of Abu Ghraib abuse were seen around the world (AP/Courtesy The New Yorker)
A number of high-profile investigations sought to establish both who exactly was responsible for the treatment, and how widespread the practice was.
Three soldiers have already been sentenced for their role in the Abu Ghraib abuse, and more trials are to follow in the new year. But inquiries have not pinned responsibility on any senior army officials outside the prison and there have been no high-level resignations.
But the allegations have kept coming. In the months since the Abu Ghraib scandal broke, lawsuits and investigations have shed light on other incidents of abuse of prisoners in US custody around the world.
According to documents prepared for internal Pentagon use but obtained by the American Civil Liberties Union (ACLU) under freedom of information legislation, 10 "substantiated" incidents of detainee abuse occurred in Iraq over the past two years - apart from the Abu Ghraib incidents.
They resulted in 11 court martial convictions and three lesser punishments. The most severe sentence - one year's confinement - was handed down to a marine who had tortured a detainee with electrical shocks.
Three marines had also been convicted over the "mock executions" of prisoners in which two juveniles were forced to kneel over shallow graves as a pistol was fired.
The ACLU obtained the reports to try to bolster a lawsuit over abuse in Iraq and the US prison at Guantanamo Bay.
The Pentagon argued that the very existence of the documents proved that such charges, if substantiated, were acted upon.
"When we have credible allegations of abuse we take them seriously and investigate them," said a spokesman.
Other documents obtained by the ACLU under the same legislation have also shone the spotlight on the situation in Guantanamo Bay.
Memos between FBI officials express concern at the tactics being used, suggesting that detainees - mostly suspected Taleban and al-Qaeda fighters captured during the war in Afghanistan - were shackled to the floor in foetal positions for more than 24 hours at a time, left without food and water and allowed to defecate on themselves.
It was also alleged that military interrogators at Guantanamo Bay impersonated FBI agents, apparently to avoid possible blame in subsequent inquiries, and that this method was approved by Deputy Defence Secretary Paul Wolfowitz.
"Top government officials can no longer hide from public scrutiny by pointing the finger at a few low-ranking soldiers," said ACLU executive director Anthony Romero.
The Pentagon has not commented on the latest charges, but spokesman Bryan Whitman denied that Mr Wolfowitz had approved impersonation techniques.
The US army also admitted last week that eight detainees had died in its custody in Afghanistan - two more than previously acknowledged.
The army's admission came after the campaign group Human Rights Watch said it knew of three new incidents which had come to light in documents made available under the Freedom of Information Act.
The organisation said it knew of only two US personnel being charged with any crime.
They included a solider who received an administrative punishment over the death of an Afghan man in 2002, thought to be the first known death of a prisoner in US custody.
An administrative punishment ranges from a verbal reprimand to discharge from the army.