(1)The provisions of a bulk acquisition warrant may be modified at any time by an instrument issued by the person making the modification.
(2)The only modifications that may be made under this section are—
(a)adding, varying or removing any operational purpose specified in the warrant as a purpose for which any communications data obtained under the warrant may be selected for examination, and
(b)providing that the warrant no longer authorises or requires the carrying out of activities falling within section 158(6)(a).
(3)In this section—
(a)a modification adding or varying any operational purpose as mentioned in paragraph (a) of subsection (2) is referred to as a “major modification”, and
(b)any other modification within that subsection is referred to as a “minor modification”.
(4)A major modification—
(a)must be made by the Secretary of State, and
(b)may be made only if the Secretary of State considers that it is necessary on any of the grounds on which the Secretary of State considers the warrant to be necessary (see section 158(1)(a)).
(5)Except where the Secretary of State considers that there is an urgent need to make the modification, a major modification has effect only if the decision to make the modification is approved by a Judicial Commissioner.
(6)A minor modification may be made by—
(a)the Secretary of State, or
(b)a senior official acting on behalf of the Secretary of State.
(7)Where a minor modification is made by a senior official, the Secretary of State must be notified personally of the modification and the reasons for making it.
(8)If at any time a person mentioned in subsection (6) considers that any operational purpose specified in a warrant is no longer a purpose for which the examination of communications data obtained under the warrant is or may be necessary, the person must modify the warrant by removing that operational purpose.
(9)The decision to modify the provisions of a warrant must be taken personally by the person making the modification, and the instrument making the modification must be signed by that person.
This is subject to subsection (10).
(10)If it is not reasonably practicable for an instrument making a major modification to be signed by the Secretary of State, the instrument may be signed by a senior official designated by the Secretary of State for that purpose.
(11)In such a case, the instrument making the modification must contain a statement that—
(a)it is not reasonably practicable for the instrument to be signed by the Secretary of State, and
(b)the Secretary of State has personally and expressly authorised the making of the modification.
(12)Nothing in this section applies in relation to modifying the provisions of a warrant in a way which does not affect the conduct authorised or required by it.