President-elect Donald Trump got straight to tweeting on Tuesday morning, first by going after CNN for their support for Democratic nominee Hillary Clinton during the election, which he won. He then went after people who burn the American flag.

In one tweet, Trump suggested that people burning the flag — a form of speech with which he does not agree — should either be imprisoned or stripped of their citizenship.

Burning the American flag is protected by the First Amendment. This was decided in the 1990 Supreme Court case, United States v. Eichman. 

According to the ACLU, "Flag burning and desecration is offensive precisely because it is political. Experience shows that the way to fight political expression with which one disagrees is not to outlaw it, as Congress has repeatedly sought to do, but to express disapproval."

Trump wrote of flag-burning, "Nobody should be allowed to burn the American flag - if they do, there must be consequences - perhaps loss of citizenship or year in jail!"

It remains unclear about what exactly he was referring to, but the people of Twitter had a lot to say about his controversial message.