Last Friday it was revealed in the Washington Post that the Chinese hacked into crucial U.S. military networks, gaining access to dozens of weapons systems. "This is billions of dollars of combat advantage for China. They've just saved themselves 25 years of research and development. It's nuts," a senior official told the Post.

While certainly troubling, it isn't the first time the U.S. goverment has found itself with a major intelligence leak or security breach. From the Mexican-American war to WikiLeaks, the U.S. has long been dealing with headline-grabbing intelligence leaks.

Here is a list of 15 of the most famous security leaks/breaches in history.

Hutchinson Letters

In 1772, while serving as a colonial agent in London, Benjamin Franklin came into possession of several previously delivered letters written by Thomas Hutchinson, Governor of Massachusetts, to the British government. Franklin felt the letters misrepresented an ongoing acrimonious debate in Massachusetts about the extent of British involvement in the colonies. He felt his associates in Massachusetts should know what Hutchinson had said and sent the letters to a friend in Boston, stipulating that they could not be published. But the Boston Gazette published the letters, and the angry populace forced Hutchinson back to England. Franklin lost his position as Postmaster General because of his role in leaking the letters, and his reputation in England was tarnished.

Treaty of Guadalupe Hidalgo

In March of 1848, reporter John Nugent obtained a copy of the treaty between the U.S. government and the Mexican government to end the Mexican-American War. He published the treaty in the New York Herald before either party signed it or it was ratified by Congress. Called before Congress, he refused to reveal his source and was held for a month in the capitol building before being released. Ten years later, Nugent was given a job as a special agent by President James Buchanan, who it is suspected was the very government official to give Nugent the treaty in the first place.

Enigma machine

During World War II, German military operations, from invasion plans to U-boat operations in the Atlantic Ocean, were coordinated using an advanced coding network called the Enigma. But little did the Germans know that the Polish intelligence agency had actually cracked earlier versions of the code as far back as 1932. The Poles shared their decoding techniques with the British government, who in turn shared them with the American government. Codenamed “Ultra,” the Allied efforts that cracked the German security codes were kept secret throughout the entire war and, according to Winston Churchill, were one of the key reasons the Allied governments were able to win the war.

Operation Mincemeat

In 1943 the Allied forces of America and Great Britain were preparing to invade the island of Sicily. To keep the invasion secret, they orchestrated their own security breach. The Allies sent a body floating toward German/Italian occupied territory with documents detailing a fabricated Allied invasion of Sardinia and Greece. The Germans found the body and plans and accepted the false plans as true. As a result, the Allied invasion of Sicily was mostly a surprise to Axis command.

After the invasion, whenever actual Allied plans landed in German hands, they would often refuse to believe them, assuming they were simply another Allied ruse.

The Rosenbergs

Though the United States and the Soviet Union were allies in WWII, trust between the two nations was virtually nonexistent, and consequently, the U.S. kept the Soviets out of the loop while developing the nuclear bomb. After the bombs were dropped on Japan, the U.S. seemed to have a nuclear monopoly. In 1949, however, the Soviets successfully tested their own nuclear device, surprising everyone with how quickly they had built their own bomb.

It was later discovered that a spy ring, run by Julius Rosenberg, had been supplying the Soviets with American nuclear research throughout the war. Julius and his wife, Ethel, were tried and executed for aiding the enemy in a time of war.

Pentagon Papers

The early '70s were no stranger to corruption, lies and scandal, but one of the most shocking leaks was the Pentagon Papers.

Daniel Ellsberg, a military contractor at the time, obtained a security document titled "United States-Vietnam Relations, 1945-1967: A Study Prepared by the Department of Defense." It claimed that some of the fundamental reasons of the Vietnam War and other U.S. involvement in Indochina were deceptive. Ellsberg sent portions of the report to the New York Times, which published the papers, causing a huge backlash against the few politicians still supporting the war.


After five men broke into Democratic Party headquarters in the Watergate complex, Washington Post reporters Bob Woodward and Carl Bernstein were contacted by a mysterious government official, who tipped them off that it was more serious than just a robbery. Using the source codenamed “Deep Throat,” Bernstein and Woodward eventually uncovered the huge scandal that exposed Nixon’s direct role in the break-in.


Iranian Shia cleric Mehdi Hashemi revealed to the world in a Lebanese magazine the Reagan administration's complex plan of paying the Israelis to arm the Iranians — while still supporting Iraq in their war against Iran. It also detailed that funds from the Iraq arms sales were used to fund anti-communist death squads in Nicaragua.

Hashemi was executed later that year by the Iranian government. This leak remains one of the defining moments of Reagan’s presidency.

Valerie Plame Wilson

In a July 2003 Washington Post story, Deputy Secretary of State Richard Armitage revealed that Valerie Plame was in fact an undercover agent for the CIA. It is believed that Bush administration officials purposely leaked the information to the press after Valeria's husband, Joseph Wilson, wrote a series of op-eds criticizing the war in Iraq. Valeria resigned from the CIA, and the organization requested a full criminal investigation into the matter.

Abu Ghraib

After accounts of prisoner mistreatment at the Abu Ghraib prison in Iraq surfaced in 2004, investigative journalist Seymour Hersh published in the New Yorker photos leaked to him. The photos showed obvious instances of torture, cruel and unusual punishment and general prisoner mistreatment by military prison guards. The photos caused a public uproar. Eventually 11 military personnel were convicted of charges, with some serving prison sentences of up to 10 years.

Downing Street memo

In 2005 the Downing Street memo, containing notes between President George W. Bush and British officials concerning the plans for the upcoming invasion of Iraq, was published by The Sunday Times. The notes revealed that the U.S. intelligence justifying the Iraq War was shaky at best and that the links between Saddam Hussein and terrorism were not as strong as publicly stated. Also noted was the fact that Iraq likely had fewer weapons of mass destruction than originally perceived.

Department of Veteran Affairs breach
Department of Veteran Affairs

In May of 2006, a laptop with an external hard drive was stolen from a home in Maryland. It belonged to an analyst for the Department of Veteran Affairs, who failed to report to the department that the laptop had been stolen. This allowed whoever stole the laptop to break into the VA database and gain access to more than 26 million veterans' personal information. It is estimated that $100-500 million had to be spent to cover possible losses from the breach.


In the fall of 2009, a group or individual hacked into servers used by the Climate Research Unit and copied thousands of documents about climate change.

Climate change critics, those denying the reality of human-caused climate change, argued that the information showed that global warming was a scientific conspiracy. But CRU claimed that these emails were taken out of context and were only an exchange of ideas.

Because this breach happened weeks before the Copenhagen Summit on climate change, many believe this was a smear campaign intended to ruin the conference.

Afghanistan War diary

On July 25, 2010, WikiLeaks gave The New York Times, The Guardian and Der Spiegel over 91,731 documents from a six-year period of the Afghan War. The documents showed that the war, often forgotten due to the media coverage of the Iraq War, was far more brutal and costly than the public had originally perceived. Numerous friendly fire incidents and civilian casualties were revealed, as well as information that Pakistani and Iranian intelligence was working with the Taliban.

Iraq War logs

In October of 2010, the single largest security breach in U.S. history occurred when the website WikiLeaks published field reports filed between 2006 and 2009, highlighting the true number of civilian casualties suffered in the Iraq War. After this leak, further investigation was conducted. It was revealed that military troops classified some civilian casualties as enemy casualties, such as two Reuters reporter deaths in 2007. The number of civilian deaths was revised.

Eventually, Army Private Bradley Manning was accused of leaking the classified information to WikiLeaks and is currently undergoing investigation with a trial to start June 3, 2013.