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The CIA is touting its version of eco-shredding on Earth Day, saying it's found a way to make the "burn after reading" process environmentally friendly.

The intelligence agency says classified papers are shredded and burned using an on-site incinerator, which then generates steam to heat water at CIA headquarters.

The CIA says the process reduces landfill waste by nearly 1,000 tons per year. And its employees also recycle more than three tons of plastic, glass, cardboard and other materials annually.

The agency didn't offer to show reporters how its secret shredding is done, however.