The US Constitution does not guarantee freedom from fear. I believe that its writers intended freedom from fear though. They did this by being specific about what they thought was necessary to ensure individual liberty.
Imagine if they had been so vague as to guarantee "freedom from fear", there'd be no guns, no planes, no sex, no motor cars, not a single luxury.
There are laws against speech that incites rioting. This is one of those after the fact things I think. This law should only be exercised punitively and not as a preventative, IMO.