It's interesting how much people still talk about metadata collection (protected behind the requirement of itemized FISA court approval) because "big mean US is evil" while ignoring events like this.
>From the final weeks of 2010 through the end of 2012, according to former American officials, the Chinese killed at least a dozen of the C.I.A.’s sources. According to three of the officials, one was shot in front of his colleagues in the courtyard of a government building — a message to others who might have been working for the C.I.A.
If you don't want to do the time, don't do the crime. You don't just stumble into being an informant for a foreign power.