Summary of the Decision 1. Void for Vagueness The “information with a content that commits an activity prohibited by the National Security Act” refers to information committing acts that satisfy the elements of a crime set forth in Article 3 or 12 of the National Security Act or information that constitutes the means, target or the act itself that comprise the elements of a crime. The present provisions merely provide that information which contains the acts prohibited under the National Security Act should be prevented from circulation by simply considering the contents of the information, and do not address the issue of whether an inaction of not deleting posted information by the manager or operator violates the National Security Act. For this reason, it can be concluded that the present provisions are not so unclear as to hamper the predictability of offenders or enable arbitrary execution of administrative agencies, and are therefore not inconsistent with the principle of void for vagueness. 2. Freedom of Press The telecommunications network, particularly the Internet, provides promptness, extensiveness and duplicability of a whole new level compared to the existing communication tools, and it is highly likely that ineffective regulation of such anti-state activities posing a threat to national safety as circulating “information with a content that commits an activity prohibited by the National Security Act” will rapidly spread the threat to national safety and people’s life and freedom. Therefore, the legislative purpose to ban circulation of such information has good reason. The decision on whether an activity constitutes an anti-state activity that jeopardizes national safety is left to the legislature as the people’s