This is a comparison of the law of the United States (U.S.) and United Kingdom (UK) relating to the authority to investigate terrorism. It focuses primarily upon the procedures for conducting searches and seizures including the interception of communications, arresting and detaining suspected terrorists, and control orders restricting the activities of suspected terrorists. The most obvious difference between the laws of the two countries is that in the UK approval of extraordinary authority including the issuance of warrants often remains an executive function and in the United States the task more often falls to the courts. In addition, authority in the United States only roughly approximates at best the power of UK officials to arrest and detain suspected terrorists and to subject them to control orders. On the other hand, U.S. officials appear to enjoy greater flexibility in the use of intercepted communications for evidentiary purposes. Many of the differences can be understood in light of the reach of the Fourth Amendment to the United States Constitution. The Fourth Amendment condemns unreasonable governmental searches and seizures. It applies where there is a justifiable expectation of privacy and does not apply there is not. It does not apply to consensual searches nor to the overseas search of the property of foreign nationals with no substantial connection to the United States. The Amendment begins with the presumption that a search or seizure is unreasonable unless conducted pursuant to a warrant issued by a neutral magistrate and upon a showing of probable cause to believe a crime has been committed. There are many circumstances, however, in which a search or seizure will be considered reasonable notwithstanding the absence of a warrant or of probable cause or of both. Thus, border inspections require neither warrant nor suspicion, nor does a procedure which allows officers to stop and search parolees. Incident to a valid arrest, law enforcement officers may search a suspect without probable cause to believe the suspect possesses evidence or a weapon. They may arrest a suspect without a warrant when they have probable cause to believe he has committed a felony, and may conduct a brief investigative stop with less than probable cause when, given all of the circumstances, they have "a particularized and objective basis for suspecting"an individual is engaged in or about to engage in criminal activity. When acting in the interests of certain special needs, such as highway safety or student health and safety, government officials may engage in warrantless, suspicionless searches. When acting solely in the name of national security, government officials may not engage in warrantless searches and seizures relating to a suspected domestic terrorist. Whether and to what extent they enjoy greater latitude when focused on the activities of foreign powers and their agents is less clear. The statutory basis for stop and searches by the police in the UK is contained in the Police and Criminal Evidence Act 1984, which provides the police can stop and search and individual if they have reasonable suspicion that a crime has been, is being, or is about to be committed. Statistics show that under the provisions of this Act the police stopped black people six times more frequently than white people and Asian people two times more frequently. The police were provided with broader authority to stop and search people under the Terrorism Act 2000 that permits officers, with authorization from a senior officer, to stop and search anyone to prevent terrorism. Statistically, Asian and black people are respectively four and five times more likely to be stopped than white people under this Act. These statistics, combined with the Code issued under the Police and Criminal Evidence Act and the Home Office Stop and Search Interim Guidelines provide that while the police must "not discriminate against members of minority ethnic groups when they exercise these powers ... [t]here may be circumstances where it is appropriate for officers to take account of a person's ethnic background when they decide who to stop in response to a specific terrorist threat (for example, some international terrorist groups are associated with particular ethnic groups, such as Muslims)." This Code of Practice has given rise to the claim that the British police use ethnic and religious profiling in their policing, a claim that both the government and the police have actively worked to dismiss. The government has noted that the enactment of the recent anti-terrorism laws led to "a palpable increase in stopping and searching of people of Asian origin in particular." The government expressed concern that tensions with the Muslim community in particular are not exacerbated, because it is believed that the isolation and the stigmatization, perceived, or otherwise, contributes towards the disenfranchising of Muslims, providing extremists with the opportunity to recruit these individuals. An expert witness in a panel reviewing the use of anti-terrorism stop and search powers has noted "one of the biggest dangers of counter-terrorism policing must be that it will grow the very terrorism which it seeks to defeat." Against this background, in the wake of the London bombing in July 2005, the Chief Constable of British Transport Police (BTP) publicly stated: "We should not waste time searching old white ladies. [Searches are] going to be disproportionate. It is going to be young men, not exclusively, but it may be disproportionate when it comes to ethnic groups." The government quickly distanced itself from this remark noting that intelligence-led stop and searches should be utilized rather than stereotyping ethnic minorities because "tackling terrorism is absolutely dependent on the confidence of these communities to feel that they can come forward, give information and be part of the fight against this threat." In the United States as noted earlier, the Fourth Amendment permits parolees to be stopped and searched without warrant or suspicion. And law enforcement officers may conduct a brief investigative stop when given the circumstances they have "a particularized and objective basis for suspecting" that criminal activity is afoot. Nevertheless invidious racial, ethnic, or religious discrimination in law enforcement is unlawful, and the consideration of such factors standing alone "and sometimes even in tandem with other factors, does not generate reasonable suspicion for a stop." Police powers in the UK under the Terrorism Act 2000 are wide-ranging and there are concerns over opportunities for abuse. The Act permits investigations into the resources of proscribed organizations and the commission, preparation, or instigation of acts that are offenses under the Act. Police can arrest individuals without a warrant based on a reasonable suspicion that they have been involved in the preparation, instigation, or commission of acts of terrorism, regardless of whether police believe the suspect is committing or has committed a crime. The government justified this "pre-emptive power of arrest" by stating that the delay in collecting sufficient information for an arrest warrant would, in some cases, be too late to prevent the terrorist act. There are no federal statutory provisions in the United States comparable to the British authority to arrest suspected terrorists. Under the Fourth Amendment, the hallmarks of a reasonable arrest are probable cause and a warrant issued by a neutral magistrate. The Amendment does allow warrantless arrests based on probable cause under some circumstances and permits brief investigative stops and border inspections without a warrant and less than probable cause, but there is nothing the equivalent of a "pre-emptive power of arrest." The government in the UK has faced the difficult task of balancing the rights of individuals, which now have extensive statutory protection under the Human Rights Act 1998, with the security of the state. The incorporation of the European Convention on Human Rights [the ECHR] into the domestic law of the UK by the Human Rights Act 1998 altered the legal climate of the UK and resulted in the specific prohibition of detention for the sole purpose of preventing a crime being specifically prohibited, save in certain circumstances prescribed by law. While the ECHR is not a new doctrine of law, but merely sets out the rights that individuals in Britain have long enjoyed under the common law, the impact of the ECHR on the domestic laws of the UK is evident. Cases challenging British laws are noticeable and ever increasing in number. The UK has had lengthy experience in indefinitely detaining those suspected to be terrorists without trial in Northern Ireland. Under the Prevention of Terrorism (Temporary Provisions) Act 1984 (PTA), the Secretary of State could authorize the detention of a person for up to seven days. In 1988 the European Court of Human Rights ruled that this was a breach of article 5(3) of the ECHR unless it was judicially authorized, resulting in the government derogating from that article in order to lawfully retain this provision of the PTA. The use of these powers was controversial and in response to increasing violence. The result of the internment of almost 2,000 predominantly Catholic men was greater civil disturbances and a "diminished respect for the rule of law in Northern Ireland." It was widely reported that the use of internment was "among the best recruiting tools the IRA ever had." It was against this background and experience that the government had to decide the most effective, least controversial, and least likely to succumb to legal challenges in which to address individuals whom the government suspects to be international terrorists or threats to national security, but whom it cannot deport. This issue was tackled during the drafting of the TA, when alternative options to derogation from the ECHR were considered. It was finally decided that individuals could be detained for up to forty-eight hours after arrest without charge. Critics of the TA regarded this provision as providing for "incommunicado detention" and unnecessary because previously individuals detained under similar provisions were rarely charged with a terrorist offense. Despite this criticism the period of detention permitted under the TA has been extended by successive acts—from forty-eight hours to fourteen days by the Criminal Justice Act 2003 and from fourteen days to twenty-eight days by a highly contentious provision in the Terrorism Act 2006. The detention under this provision, for an initial period of forty-eight hours, is then reviewed by a judicial authority and is then renewable for seven day periods up to a maximum of twenty-eight days, with a senior judge considering applications for detainment for the final fourteen days.