"It is legitimate for states to exempt information whose release would be prejudicial to national security from their disclosure laws. But in order to insure that this exemption is not abused it is important to develop an acceptably narrow definition of what constitutes national security. To this end, the Centre for Law and Democracy has produced a paper examining how national security should be defined in the context of information disclosure. The paper was produced as a contribution to the “Principles on National Security and the Right to Information” currently being developed by the Open Society Initiative."
Centre for Law and Democracy. Defining the Scope of National Security: Issues Paper for the Open Society Justice Initiative National Security Principles Project. May 2011