It would be great to ban posting threats or sending messages containing threats by coding an Algorithm that recognizes the commonly used words for that.
Too easily gamed. 733T-speak is enough to defeat a regex filter. "Shakespearean" insults and threats get past the smaller LLMs, too. Any LLM smart enough to defeat a level two troll is not something a client can afford to run, (or even most relays). Actively shared mute lists works for email