Making threats has been a "something" that's considered a crime for... well, a long time. Typically the law requires that the threat be at least somewhat believable in order to be successfully prosecuted, but there are certain types of threats which are criminal regardless of ability to be carried out (e.g., threatening to plant a bomb in a public square is a crime, even if you have no way of building or planting the bomb).
Threatening seems so much like thoughtcrime.