The armed contractors, who directly serve the interests of the US occupation, now number 40,000 in Afghanistan and Iraq. These numbers are set to increase substantially; in August it was announced that the Obama administration intends to double the number of private mercenaries in Iraq, as it reduces the number of soldiers under US uniform in the Obama administration’s “draw-down.”

The mercenaries, some of whom earn more than $500 per day, are accountable to no one. Soon after the US invasion of Iraq, Paul Bremer issued “Order No. 17,” giving security firm employees total immunity from Iraqi laws. Nor has any US court punished the contractors, even for known instances of murder. They are also not under the jurisdiction of the US military, freeing them from the court martial and even the often-flouted rules of engagement laid out in the US Army Field Manual.

WikiLeaks documents analyzed by Al Jazeera, the Arab-language media service, reveal at least 14 previously unknown cases in which employees of the most infamous private security firm, Blackwater International, fired on civilians. These attacks resulted in 10 confirmed deaths and seven serious injuries.

Blackwater, now known as Xe Services, is most notorious for a 2007 attack it carried out in Baghdad’s crowded Nissour Square, killing 17 civilians and seriously wounding 18 more. Five Blackwater mercenaries were charged with murder, but a US judge ruled the prosecution had engaged in misconduct and threw the case out.

The documents, field reports from US soldiers, reveal that Blackwater carried out many other killings that were not acknowledged by the US military or the Iraqi government, and that went unreported by the western media.

In February, 2006, as Blackwater mercenaries were escorting US diplomats through Kirkuk (part of a $465 million contract the State Department had awarded the firm), they opened fire on civilians, killing two. Protests erupted in Kirkuk after these murders.

In May of 2006, Blackwater guards let loose “uncontrolled fire” in north Baghdad, killing an ambulance driver, Jasem Abed Sarhan. The shooting apparently came as blind retaliation for their vehicle hitting a roadside bomb. After the killing, Blackwater refused to cooperate with a US army investigator.

In May of 2005, US soldiers witnessed Blackwater contractors “shoot up a civilian vehicle,” along the “Route Irish,” the code name for the road to the Baghdad airport, before speeding off in a white armored vehicle. The driver of the civilian vehicle was killed, and his wife and daughter were maimed. The field report noted that the contractors also fired in the direction of the US soldiers during the incident.

In April 2006, US soldiers came upon the scene after Blackwater mercenaries had gunned down three civilians in Baghdad. Blackwater guards claimed they had been engaged in a shootout with insurgents, who had escaped.

No Blackwater mercenary has ever been punished for killing an Iraqi. Only Monday the US Justice Department announced it was dropping charges against Andrew J. Moonen, a Blackwater employee who killed the bodyguard of an Iraqi Vice President on December 24, 2006. Moonen has admitted to being drunk at the time of the shooting, which took place in Baghdad’s Green Zone.

Blackwater, since February of 2009 known as Xe Services, still receives lucrative CIA and State Department contracts. On October 1, the Obama administration renewed Xe Services’ Afghanistan contract for another five years. The next day, the US-controlled Afghan regime of President Hamid Karzai banned it and seven other private contractors from operating in the country, in a bid to ease popular anger against the Kabul government’s complicity in crimes against the population.

Blackwater was not the only private security firm that killed and brutalized Iraqis. According to the Guardian, which also analyzed the newly-released documents, in terms of the number of incidents uncovered in the WikiLeaks documents, Blackwater is “closely followed by Erinys, a British private security company registered in the Virgin Islands, which seems to have an unusually high number of vehicle crashes.”

The New York Times also found incidents of security contractors attacking civilians. Mercenaries working for the Romanian firm Danubia Global killed three Iraqis in Falluja in 2006, “then refused to answer questions on the episode,” it reports.

According to another military report, in July 2009 contractors with a firm known as 77th Security Company entered a neighborhood in the northern city of Erbil and began a shooting spree. This set off a gunfight with an off-duty police officer, during which three women were wounded. The field report concluded that “this drunken group of individuals” was “out having a good time and firing their weapons.”

As chilling as the new revelations are, they vastly underestimate the number of killings by private security firms. Firstly, they include only instances in which US soldiers directly observed the contractors in action, or came upon the scene soon after violence had been committed.

Secondly, as Pratap Chatterjee of the Guardian notes, field reports on mercenary attacks appear to understate their gravity.

Chatterjee was surprised when he could not find information related to the Blackwater massacre in Nissour Square. “Eventually, I tracked down the incident by trying a few other methods,” he writes. “It is easy to see why I missed the record: there is no mention of the company, or the location, and even the death toll is incorrectly recorded as nine, suggesting that the Pentagon casualty record is incomplete.”

He continues, “Quite possibly, there were many more incidents in which civilians were injured, or even killed, which were never reported. Some of the reports may have been altered before they were entered into the military system. But given the other records that I found, at the very least, WikiLeaks has revealed that Blackwater and other private security companies are guilty of many more injuries and killings than the media have previously reported.”

In contrast, the American press has sought to shield the private security companies.

The New York Times article concerns itself primarily with the dangers the mercenaries themselves confronted. It notes the frequency with which US or Iraqi government troops accidentally fired on the contractors’ speeding vehicles, generally unmarked SUVs and pickup trucks; the many traffic deaths among contractors; deaths resulting from IED explosions on their unarmored vehicles; instances in which confused mercenaries wound up accidentally shooting at each other; and two cases in which contractors murdered their own colleagues.

Though killings reported by Al Jazeera had not been previously reported, this did not stop the American media from claiming the opposite. In its Tuesday editorial, the Washington Post asserted that all “the incidents were extensively reported by Western journalists and by the US military when they occurred.” This shameless lie is designed to hide the Post’s complicity in the cover-up of these and countless other crimes against the Iraqi people.

Significantly, security firms are taking measures to defend themselves against charges of war crimes. On Tuesday two requested that a federal appeals court grant their employees immunity from lawsuits brought by torture victims and bereaved relatives of victims murdered at the notorious Abu Ghraib prison in Iraq.

Lawyers for L-3 Communications of New York and CACI International of Virginia argued that “war on terror” rules—which prevent US soldiers and intelligence operatives from being sued in US courts—should apply to private firms working under government contracts.