Days after new documents provided by Edward Snowden showed that the National Security Agency was deploying malware allowing it to pose as Facebook and other sites in order to intercept data, the NSA is now denying this characterization and insisting that what it does is legal.

“NSA uses its technical capabilities only to support lawful and appropriate foreign intelligence operations, all of which must be carried out in strict accordance with its authorities,” says the document, which was published Thursday on the NSA’s Twitter account . (Yes, the NSA has a Twitter account.)

“Technical capability must be understood within the legal, policy, and operational context within which the capability must be employed. NSA's authorities require that its foreign intelligence operations support valid national security requirements, protect the legitimate privacy interests of all persons, and be as tailored as feasible. NSA does not use its technical capabilities to impersonate U.S. company websites. Nor does NSA target any user of global Internet services without appropriate legal authority. Reports of indiscriminate computer exploitation operations are simply false.”

This explanation appears to deny a particular allegation that was never made. By saying the “NSA does not use its technical capabilities to impersonate US company websites”—the NSA appears to overly simplify what The Intercept actually reported:

In one man-on-the-side technique, codenamed QUANTUMHAND, the agency disguises itself as a fake Facebook server. When a target attempts to log in to the social media site, the NSA transmits malicious data packets that trick the target’s computer into thinking they are being sent from the real Facebook. By concealing its malware within what looks like an ordinary Facebook page, the NSA is able to hack into the targeted computer and covertly siphon out data from its hard drive. A top-secret animation demonstrates the tactic in action.

Regardless, the NSA’s and the Obama Administration's explanations aren’t convincing to Facebook CEO Mark Zuckerberg.

On his public Facebook page, he wrote Thursday that he was “confused and frustrated” by the government’s behavior.