An administration official confirms that the OMB sent the email, adding that it follows guidance the office made earlier this week telling agencies to review their information security procedures.
"The recent disclosure of U.S. Government documents by WikiLeaks has resulted in damage to our national security," the email reads. "Federal agencies collectively, and each federal employee and contractor individually, are obligated to protect classified information pursuant to all applicable laws, as well as to protect the integrity of government information technology systems."
It goes on (emphasis theirs):
Accordingly, agencies are requested immediately to send a notice to all agency employees and contractors reminding them of their obligations to safeguard classified information. A model notice, for use or adaptation by each agency, is attached to this memorandum. Agencies are responsible for communicating this notice promptly to their employees and contractors. If an agency has a legitimate need for personnel to access classified information on publicly available websites, the agency head shall ensure that such access is managed in a manner that minimizes risk to government information technology systems and adheres to established requirements.
The email includes a "model notice" for each agency to use. You can see the whole thing here.
"Unauthorized disclosures of classified documents (whether in print, on a blog, or on websites) do not alter the documents' classified status or automatically result in declassification of the documents," it reads. "To the contrary, classified information, whether or not already posted on public websites or disclosed to the media, remains classified, and must be treated as such by federal employees and contractors, until it is declassified by an appropriate U.S. Government authority."
Earlier today, TPM reported that the Library of Congress, an internationally respected library and the research arm of Congress, had blocked Wikileaks' web site from its staff computers and visitors' wireless network. The State, Commerce and Education departments have also directed employees not to view the cables.
Late update: OMB spokeswoman Moira Mack explains a little more:
This template notice (for adaptation and issuance by individual agencies) restates and reinforces existing restrictions on access to classified documents by unauthorized personnel or on computers that access the web via non-classified government systems. It reinforces existing requirements to protect the integrity of non-classified government systems, and to prevent spillage of classified material onto non-classified systems.