Holding a picket sign is a form of symbolic speech because it is an action that expresses an idea in a nonverbal way. Other types of nonverbal expression may involve waving flags, participating in sit-ins, and wearing buttons or articles of clothing that have symbolic meaning. Other examples of symbolic speech include passing out leaflets, asking for petition signatures, marching down streets and parading in front of buildings.
Flag burning is a controversial form of symbolic speech that sometimes occurs during picketing activities. While burning a U.S. flag is offensive to some people, flag burning is protected under the First Amendment. In the case of Texas v. Johnson, 491 U.S. 397, the majority opinion of the U.S. Supreme Court noted that outrage over flag burning does not justify suppressing this form of symbolic speech. Therefore, flag burning is exempted from any laws attempting to punish people that engage in this activity.
Certain forms of symbolic speech are protected in the United States because the U.S. government cannot regulate or restrict the specific content of speech. Any regulations regarding speech must be unrelated to the expression of ideas and viewpoints. However, there are some forms of speech that fall outside First Amendment protection. This includes speech that contains content that is deemed to be obscene, defamatory or inflammatory in some way.