Ask HN: HN blocked today by a major .gov; your thoughts?

Reportedly, a large US government institution blocked the access to news.ycombinator.com today.

Apparently, the HN site was identified as either a security threat or inappropriate for the government.

Does anyone know anything about it? What are your thoughts?

Is this as trivial as someone being confused by the word 'Hacker' in the page title?

FWIW, other sites such as slashdot, reddit, digg are accessible.