For decades, the CIA used Swiss company Crypto AG, which it covertly owned, to spy on both adversaries and allies, according to leaked documents published last week.

The CIA called it "the intelligence coup of the century," but it's far from the only state secret to revealed in recent years.

Documents leaked by whistleblowers like Edward Snowden and Chelsea Manning have shed light on everything from offshore tax havens to CIA torture to the NSA's mass surveillance of American citizens.

Here are some of the most important things we've learned from the biggest leaks of the past decade.

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Since the Cold War, more than 120 countries reportedly trusted a Swiss company Crypto AG to safeguard their most secret messages. However, few of them knew that, according to a leaked report published last week by the Washington Post, the encrypted communications device maker was actually controlled by the CIA and its German counterpart.

The two intelligence agencies reportedly rigged the devices to let them listen in on political and military leaders, other spies, and even private companies — and make millions of dollars in profit along the way. Crypto AG helped them spy on uprisings in Latin American countries, Middle Eastern dictators, the Vatican and even the United Nations.

While the CIA report called the operation "the intelligence coup of the century," other major leaks over the past decade have shed light on some closely held state secrets.

Whistleblowers like Edward Snowden and Chelsea Manning, by sharing confidential documents with journalists and organizations like WikiLeaks, have helped expose everything from the NSA's surveillance of millions of American citizens to offshore tax havens used by world leaders and the ultra wealthy.

Here are just some of the most significant things we've learned as a result of recent leaks.