Highly Classified Document Posted

One of the email lists I am on is Steven Aftergood's 'Secrecy News'. Usually there are interesting tidbits in these emails but it isn't like I wait anxiously for my emails from this organization. Imagine my surprise when I came across a totally separate article (in the NY Times I believe) about a highly classified document that came out in his e-newsletter today. Of course I quickly checked my email and found this document (note it is a 13mg file) that is clearly listed on the document as Highly Classified but had been posted by the GAO apparently by accident. The document lists all of the nuclear "sites, locations, facilities, and activities" in the US.