Someone in the MOD apparently didn't realize that the black text boxes they used to redact sensitive information regarding the UK's nuclear-powered submarines could be easily undone by a simple cut and past command. Whoops!
The redacted sections of this report on future nuclear propulsion units for subs revealed "expert opinion about the fleet's ability to withstand a catastrophic accident" along with information on how the United States Navy protects its nuclear-powered subs, presumably including those that carry Trident nuclear missiles.
From the UK's Guardian newspaper:
The document involved was an assessment drawn up by the head of the defence nuclear safety regulator, Commodore Andrew McFarlane, concerning options for the reactors in future submarines to replace the Trident fleet.But don't worry, all's now well according to the unfailingly polite MOD:
In sections released intentionally on the parliament website, it concluded that the existing reactors were "potentially vulnerable" to fatal accidents – leading ministers to suggest new versions would be used.
Some parts of the declassified document were redacted when it was published to protect sensitive information but the technique used meant the words were still electronically available underneath.
An MoD spokesman said: "The MoD is grateful to the journalist for bringing this matter to our attention.
"As soon as we were told about this, we took steps to ensure the document was removed from the public domain and replaced by a properly redacted version. We take nuclear security very seriously and we are doing everything possible to prevent a recurrence of this."