Where's the political comment? Who's the Jon Carry they refer to in their sign?
They are safe:
Article 88—Contempt toward officials
Text.
“Any commissioned officer who uses contemptuous words against the President, the Vice President, Congress, the Secretary of Defense, the Secretary of a military department, the Secretary of Transportation, or the Governor or legislature of any State, Territory, Commonwealth, or possession in which he is on duty or present shall be punished as a court-martial may direct.”
Elements.
(1) That the accused was a commissioned officer of the United States armed forces;
(2) That the accused used certain words against an official or legislature named in the article;
(3) That by an act of the accused these words came to the knowledge of a person other than the accused; and
(4) That the words used were contemptuous, either in themselves or by virtue of the circumstances under which they were used.
Note: If the words were against a Governor or legislature, add the following element
(5) That the accused was then present in the State, Territory, Commonwealth, or possession of the Governor or legislature concerned.
Explanation.
The official or legislature against whom the words are used must be occupying one of the offices or be one of the legislatures named in Article 88 at the time of the offense. Neither “Congress” nor “legislature” includes its members individually. “Governor” does not include “lieutenant governor.” It is immaterial whether the words are used against the official in an official or private capacity. If not personally contemptuous, ad-verse criticism of one of the officials or legislatures named in the article in the course of a political discussion, even though emphatically expressed, may not be charged as a violation of the article.
Similarly, expressions of opinion made in a purely private conversation should not ordinarily be charged. Giving broad circulation to a written publication containing contemptuous words of the kind made punishable by this article, or the utterance of contemptuous words of this kind in the presence of military subordinates, aggravates the offense. The truth or falsity of the statements is immaterial