Counter-terrorism strategy
Types of surveillance
There are several different types of surveillance that police, intelligence agencies and public authorities have at their disposal. The type they use depends on the specifics of a case and the seriousness of the crime a suspect has committed or intends to commit.
Most surveillance is conducted covertly, meaning without the knowledge of the person under surveillance.
Communications data surveillance
This is data held by telecommunications companies and internet service providers. Examples of communications traffic data that may be acquired with authorisation for a specified operation monitored include:
- names
- addresses
- telephone numbers - to find out who is called and when, but not the content of calls
- IP addresses - when a session online started and ended, and when an email server was accessed, but not the website
- addresses viewed
- geographical location of the calling or the called parties
Communications data surveillance does not monitor content.
Communications data surveillance is an important tool for the police, intelligence agencies and other public authorities, for example, the Department of Work and Pensions looks at communications data when investigating benefit fraud.
When can communications data surveillance be used?
A strict 'necessity' test must be met before communications data can be accessed. This type of surveillance will only be approved if it's:
- in the interests of national security
- to prevent or detect crime, or prevent disorder
- in the interests of the economic well-being of the UK
- in the interests of public safety
- to protect public health
- to assess or collect tax, duties, levies or other monies owed to a government department
- to prevent death, injury or damage to a person's physical or mental health in an emergency
There are further restrictions of purposes for which some public authorities may seek to acquire communications data, limited to:
- to assess or collect tax, duties, levies or other monies owed to a government department
- to prevent or detect crime
To obtain communications traffic data, approval is required from senior officers in a public authority.
Directed surveillance
Directed surveillance is a type of covert surveillance where police, intelligence agencies and other public authorities follow an individual in public and record their movements.
Law enforcement agencies granted 26,986 directed surveillance authorisations during 2003-2004. (Source: Annual Report of the Chief Surveillance Commissioner to the Prime Minister and to Scottish Ministers for 2003-2004.)
When can directed surveillance be used?
Authorised officials Police officers may follow anyone covertly if they have reasonable suspicion to suspect they have committed, or intend to commit, a crime. They can't follow you if they don't have a specific reason
Police require a warrant authorised by a superintendent to undertake directed surveillance. Warrants expire after three months or can be cancelled when they are no longer necessary.
Intrusive surveillance
Intrusive surveillance involves the presence of an individual on residential premises or in a private vehicle or is carried out by means of a surveillance device.
447 intrusive surveillance warrants were authorised during 2003-2004. (Source: Annual Report of the Chief Surveillance Commissioner to the Prime Minister and to Scottish Ministers for 2003-2004.)
When can intrusive surveillance be used?
Due to its invasiveness, this type of surveillance is only used to catch offenders suspected of serious crimes and authorised by a Chief Constable or Secretary of State. They are then reviewed by the surveillance commissioner (new window). This is necessary for intrusive surveillance in:
- homes
- private vehicles
- hotel bedrooms
A separate authorisation is required if the police or other law enforcement agencies plan to interfere with property or with wireless telegraphy when concealing a surveillance device.
Interception of communications
Interception refers to a type of surveillance where a communication is intercepted before it reaches its destination. Unlike surveillance of communications data, interception involves investigating the content of communications.
Types of communication intercepted include:
- mobile and landline telephone calls
- postal mail
Interception plays a crucial role in the fight against all kinds of terrorism, and protection of the UK's vital national interest. In 2003, 1983 interception warrants were authorised by the Home Secretary and the Secretary of State for Scotland. (Source: Report of the Interception of Communications Commissioner for 2003)
When can interception be used?
Due to its invasiveness, interception may only take place:
- in the interests of national security
- for the purpose of preventing or detecting serious crime
- for the purpose of safeguarding the economic well-being of the UK
- when the conduct authorised by the warrant is proportionate to what is sought to be achieved by that conduct
