The privilege of "habeas corpus" has been suspended or restricted several times during English history, most recently during the 18th and 19th centuries. Although internment without trial has been authorised by statute since that time, for example during the two World Wars and the Troubles in Northern Ireland, the "habeas corpus" procedure has in modern times always technically remained available to such internees. However, as "habeas corpus" is only a procedural device to examine the lawfulness of a prisoner's detention, so long as the detention is in accordance with an Act of Parliament, the petition for "habeas corpus" is unsuccessful. Since the passage of the Human Rights Act 1998, the courts have been able to declare an Act of Parliament to be incompatible with the European Convention on Human Rights, but such a declaration of incompatibility has no legal effect unless and until it is acted upon by the government.