I worked on a quick piece for The Intercept recently, that's up now. From the trove of documents provided by Edward Snowden is a report detailing the classified info that may have been obtained by China, after a collision between a Navy spy plane and a Chinese fighter jet in 2001.
The Navy's EP-3E plane was badly damaged and needed to make an emergency landing on China's Hainan Island. Although the crew was blamed by many for allowing secrets to fall into the hands of the Chinese government, the report makes clear that higher-ups did not provide the crew with the training or equipment needed to destroy all sensitive material on board. A very interesting read, check it out here. I was very excited to hear from The Intercept, I've been a big fan since its inception. Thank you to Philipp, my AD for this.