This even goes all the way back to the concept of "assault" in anglo-saxon legal traditions[1] (which is the simple threat part of the pair "assault and battery". Many of us use "assault" to mean a physical attack, but it seems originally to be simply causing someone to fear.)
Again, though, you are arguing that because something is the law then that in itself makes it moral and useful.
Those who make slippery-slope arguments about the vesting of power in the state seem increasingly persuasive when we see the turning of the act of speaking into a crime itself. For further examples of "European" countries which illustrate the dangers you could look at Ireland's blasphemy laws which still stand.