If you send a letter or writing that threatens to destroy or damage someone's property, or to hurt an animal, you could go to prison for up to 3 years. You must know what the letter or writing says to be in trouble. The property or animal can be yours or someone else's.

If you have a good reason for sending the letter or writing, or if you believe you have the right to do so, then you might not be in trouble. You must not have a lawful justification or excuse, or a claim of right, for your actions to be considered an offence. This means you cannot just threaten someone's property or an animal without a valid reason.