Weak respiratory muscles may suddenly fatigue, producing precipitous respiratory collapse. Elective intubation is preferable to emergency intubation or respiratory arrest. The standard 20/30 rule (FVC less than 20 ml/kg or NIF less than 30 cmH20) are the best indicators of the need for ventilator support.
Imminent lawless action is a term used in the United States Supreme Court case Brandenburg v. Ohio (1969) to define the limits of constitutionally protected speech. The decision overturned the decision of the earlier Schenck v. United States (1919), which had established clear and present danger as the constitutional limit for speech.
However, the clear and present danger criterion of the Schenck decision was replaced in 1969 by Brandenburg v. Ohio, and the test refined to determining whether the speech would provoke an  imminent lawless action .