"The most basic component of freedom of expression is the right to freedom of speech.Freedom of speech may be exercised in a direct (words) or a symbolic (actions) way. Freedom of speech is recognized as a human right under article 19 of the Universal Declaration of Human Rights. The right to freedom of speech allows individuals to express themselves without government interference or regulation. The Supreme Court requires the government to provide substantial justification for the interference with the right of free speech where it attempts to regulate the content of the speech. Generally, a person cannot be held liable, either criminally or civilly for anything written or spoken about a person or topic, so long as it is truthful or based on an honest opinion and such statements."
While it does say without government interference or regulation, states have different freedom of speech laws for the work place. The NBA is very hypocritical. Have your freedom of speech to kneel and do whatever you want during the national anthem, but when it comes to stuff on a shirt, you can only have these certain phrases.