In England, illegally obtained evidence has continuously been admissible subject to discretionary exclusion on the grounds of unfairness to the defendant in the context of the trial. In Australia, the English position was followed until R vs. Ireland (1970) 126 CLR 321, in which the High Court extended the discretion to exclude to cover the protection of the individual's rights in the course of investigation by law enforcement authorities. Since early in this century, the U.S. Supreme Court has interpreted the fourth amendment freedom from unreasonable searches and seizures so as to exclude evidence obtained in contravention of the amendment. However, in recent years the Supreme Court has moved away from this absolutist position and now follows a process of weighing the social costs and benefits of exclusions. Further, the Burger Court has moved away from defendants' rights toward public security interests. The Australian problem regarding illegally obtained evidence may lie in judges' failures to exercise their discretion to exclude such evidence. However, this position is a tenuous one, because the public interest exclusionary discretion was only firmly established since Bunning v. Cross in 1978. Finally, police who tape-record telephone conversations with hostage takers and extortionists should not be exposed to criminality, and the material so obtained should be admissible. (Author summary modified)