An unsettling report found that the USPS approved 50,000 requests last year to secretly monitor the mail of private Americans.

The requests reportedly came from law enforcement agencies and the Postal Service’s internal inspection unit, which monitors mail in connection with criminal national security investigations.

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The audit was completed last May, but got almost no real attention until now. The New York Times obtained documents through the FOIA.

The report also found that USPS approved requests to monitor mail without much information on what authorities were even looking for.

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Read more below, via the New York Times:

The number of requests, contained in a 2014 audit of the surveillance program by the Postal Service’s inspector general, shows that the surveillance program is more extensive than previously disclosed and that oversight protecting Americans from potential abuses is lax.

The audit, along with interviews and documents obtained by The New York Times under the Freedom of Information Act, offers one of the first detailed looks at the scope of the program, which has played an important role in the nation’s vast surveillance effort since the terrorist attacks of Sept. 11, 2001.

The audit, which was reported on earlier by Politico, found that in many cases the Postal Service approved requests to monitor an individual’s mail without adequately describing the reason or having proper written authorization.

In addition to raising privacy concerns, the audit questioned the efficiency and accuracy of the Postal Service in handling the requests. Many requests were not processed in time, the audit said, and computer errors caused the same tracking number to be assigned to different surveillance requests.