espionage

The balloon has been spotted over U.S. airspace for a couple days, The Pentagon decided not to shoot it down due to risks of harm for people on the ground, officials said.

Montes was highly regarded for her expertise on Cuba. But under the radar, she shared classified information with the Cuban government, including the identities of U.S. spies.

Yanjun Xu was convicted last November of economic espionage by a federal jury in Ohio.

This is the first time in U.S. history a former president has been investigated for possibly violating the 1917 law. But it's not the first time the Espionage Act has been under scrutiny, experts say.

WikiLeaks said it would appeal. The decision is a big moment in Assange's years-long battle to avoid facing trial in the U.S. — though not necessarily the end of the tale.

Russian United Nations Ambassador Vassily Nebenzia called it a "hostile" action.

Polish spies helped free U.S. intelligence operatives captured in Iraq — and continue to play an unsung role in America's spycraft around the world.

Reporter John Pomfret interviewed government officials and intelligence operatives and mined declassified files in Poland to write his fascinating story of the Polish-U.S. intelligence relationship.

Analysts say the plane is another example of China's industrial espionage.

China broke into tens of thousands of email accounts in January. Now officials fear the breach wasn't just about spying. It was to build the next generation of artificial intelligence.