Did NSA.gov suffer from a DDoS attack?

As of the posting of this story, their website is not responding. It hasn’t been responding for several hours. Is the US government’s spy agency experience a DDoS attack?

The website for the United States National Security Agency suddenly went offline Friday.

NSA.gov has been unavailable globally as of late Friday afternoon, and Twitter accounts belonging to people loosely affiliated with the Anonymous hacktivism movement have suggested they are responsible.