Antiterrorist legislation is generally characterized by emergency provisions for extending police powers, curtailing civil liberties, and ideologically reasserting State power. The Prevention of Terrorism Acts (PTA) were enacted in the United Kingdom in 1974, 1976, and 1984. No available evidence, however, indicates that the PTA have had any impact on terrorism in Great Britain or Northern Ireland. Therefore, it is suggested that antiterrorist legislation may require functions more important than preventing isolated terrorist acts. Examples are provided to indicate that police and legislators are fully aware of the PTA's benefits outside the boundaries of antiterrorism. Intelligence gathering is a main function, as well as intimidation of political activists and harassment of Irish immigrants. The PTA embody a notable contrast between legal rhetoric and practice. Legal rhetoric, both the legitimizing status it offers and its proclaimed intention of preventing terrorism, presents the screen of legitimacy for State activities to hold a community in fear. The primary value of the PTA has been in providing the British government with a legitimate means of monitoring, controlling, and gathering intelligence on political and social activities of Irish Catholics and other minorities. 57 references, 1 table.