Every socio-political group must determine when its survival necessitates proscription of subversive activity. Although some scholars feel no limitation upon speech is therefor justified, most students of the problem are agreed that when national security is at stake somewhere there must be imposed some limitations upon freedom of expression. The Blackstonian notion that, although there could be no prior restraints, anything could be punished after utterance is unworthy. Prior restraints of some kind, such as a prohibition upon publishing in time of war the sailing dates of troopships, are permissible under any rational analysis while, on the other hand, if anything can be punished after utterance severe punishments will as effectively deter communication as any prior restraint. The truth is that no objective standard can contribute much to the delimitation of liberty.
Chester J. Antieau,
Dennis v. United States -- Precedent, Principle or Perversion?,
5 Vanderbilt Law Review
Available at: https://scholarship.law.vanderbilt.edu/vlr/vol5/iss2/1