To ask the Chancellor of the Exchequer how many instances have been detected in his Department of computer (a) hacking, (b) viruses, (c) logic bombs, (d) trojan horses or (e) other types of computer misuse, whether perpetrated by authorised or unauthorised users of computers; and how many unsuccessful attempts have been recorded.

[holding answer 24 April 1989]: It is not the policy of the Treasury to make public details and circumstances of computer security incidents, their perpetrators and their success or failure, since such information might be of assistance to potential attackers.