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An "unusual top secret cable" sent to every CIA station and base around the world last week alerted officers about dozens of cases in the last several years involving foreign informants who had been killed, arrested, or most likely compromised, The New York Times reports.

The alert itself wasn't necessarily unique, but the Times notes the fact that the cable specified the number of lost informants — information that is usually kept strictly under wraps by intelligence officials — suggests that the issue is more urgent than usual. 

People familiar with the document told the Times the point was to "prod" the agency's case officers to shore up their protection and management of informants in other countries. Recruiting spies has always been a high-risk endeavor, but the cable warned that the CIA hasn't excelled in the area lately. Some reasons behind the issues are, the Times says: being too trusting of sources, underestimating foreign intelligence agencies, and moving too quickly to recruit informants while ignoring crucial risks. The last problem is known as placing "mission over security," the Times writes. That may be linked to the fact that during the "war on terror," the CIA shifted from more traditional espionage methods toward covert action and paramilitary operations. Read more at The New York Times.