It's almost impossible to do that. It's not as if the agency doesn't do backups. The data is around. You can never assume you're in a position where you don't actively have to guard it. Destroying the data makes you vulnerable.
Which is why information flows and even project names are so tightly controlled. You can route the information to the wrong department. You can mislabel it. You can attach improper security labels to it. You can make the files inaccessible other than to the director.
No sane agency destroys anything. See: The Kennedy Assassination.
It's almost impossible to do that. It's not as if the agency doesn't do backups. The data is around. You can never assume you're in a position where you don't actively have to guard it. Destroying the data makes you vulnerable.
Which is why information flows and even project names are so tightly controlled. You can route the information to the wrong department. You can mislabel it. You can attach improper security labels to it. You can make the files inaccessible other than to the director.
No sane agency destroys anything. See: The Kennedy Assassination.