5Lawful surveillance etc
(1)Conduct to which this Act applies shall be lawful for all purposes if—
(a)an authorisation under this Act confers an entitlement to engage in that conduct on the person whose conduct it is; and
(b)that person’s conduct is in accordance with the authorisation.
(2)A person shall not be subject to any civil liability in respect of any conduct of that person which—
(a)is incidental to any conduct that is lawful by virtue of subsection (1) above; and
(b)is not itself conduct an authorisation or warrant for which is capable of being granted under a relevant enactment and might reasonably have been expected to have been sought in the case in question.
(3)In this section “relevant enactment” means—
(a)an enactment contained in this Act; or
(b)an enactment contained in Part III of the Police Act 1997 (c. 50) (authorisation of interference with property and wireless telegraphy) insofar as relating to a police force.