The Food and Drug Administration carried out a broad spying operation on some of its own scientists' private emails, creating something akin to an enemies list of employees who had complained to Congress, journalists and others, according to documents uncovered by the New York Times.

According to the Times, the agency began the clandestine surveillance operation in an attempt to find the source of leaks of confidential information from the agency. Yet what began as a probe into a handful of scientists quickly grew into a wider investigation that snared thousands of emails between those outside parties who, the agency feared, were collaborating with staffers to smear the FDA.

Using simple spying software, the agency captured screenshots of five scientists' computers, ultimately creating a repository of some 80,000 pages of documents, which the Times exposed Saturday. The documents include emails from scientists to Congressional staffers, outside researchers, journalists and even President Obama, as well as some personal emails. According to the Times, the documents came to light after they were apparently placed on a public website by mistake.

The surveillance program arose out of an internal fight over the agency's review procedure, with disgruntled staffers warning that lax policies had allowed the approval of potentially dangerous medical imaging devices. The agency originally asked for a criminal investigation by the Department of Health and Human Services to determine the source of the leaks, but when that request was turned down, they resorted to spying on their own to get to the bottom of things.

The program had previously been exposed back in January, though its enormous extent was not known until now.