sending distressing letters
The finable offence, under the Malicious Communications Act 1988, of sending to someone a letter or some other article that conveys an indecent or grossly offensive message, a threat, or information that is false and known or believed by the sender to be false. Sending an indecent or grossly offensive article is similarly punishable. The sender must have aimed to cause distress or anxiety. If the material contains a threat, there is a defence similar to that available on a blackmail charge. See also harassment.