I hate to play the Devil’s Advocate, but our First Amendment stipulates that SICK and evil people also have a right to free speech.
Some speech is legally regarded as toxic:
Shouting fire in a crowded theater
While most of us favor unrestricted free speech, the definition of what constitutes "speech" and whether it presents certain defined or extreme dangers, are what is at issue. For example, there are still laws that allow law enforcement to obtain warrants and search their property when people speak about explosives. There are laws allowing officials to commit a person when the person makes a credible threat of suicide, etc.