In its latest act in the "war on terror", the US government has ordered officials to check that any information held about "weapons of mass destruction" is stored securely.
The government fears that hackers could access the details and use them to their own ends.
In a memo issued to departments yesterday, White House Chief of Staff Andrew Card said that government information "regardless of age, that could reasonably be expected to assist in the development or use of weapons of mass destruction ... should not be disclosed inappropriately". Heads of agencies have 90 days to report their findings.
The move is the latest act by a US government increasingly concerned about potential cyber-based vulnerabilities following the 11 September attacks.
The FBI this week called for more international co-ordination in the fight against hackers.