What about "Die, you people with red hair!" Can I drive down the road shouting that? Or will we need a government commission to study from time to time which gr

What about "Die, you people with red hair!" Can I drive down the road shouting that? Or will we need a government commission to study from time to time which groups it should be illegal to threaten? Maybe all threats should be illegal? Of course, it's often difficult to discern intent from speech, and some things that sound threatening might not actually be threats. Could get tricky.