Anthropologist and "nuclear culture" expert Hugh Gusterson has an interesting column in a recent edition of Bulletin of the Atomic Scientists on the nature of national security and secrets. There are many types of secrets, he writes; strict military secrets, and public secrets, denied and yet known by many. The state's greatest rage is often directed at individuals who reveal the latter, like Edward Snowden and Bradley Manning.
American leaders say they will avoid future Mannings and Snowdens by segmenting access to information so that individual analysts cannot avail themselves of so much, and by giving fewer security clearances, especially to employees of contractors such as Booz Allen Hamilton, where Snowden worked. This will not work. Segmentation of access runs counter to the whole point of the latest intelligence strategy, which is fusion of data from disparate sources.