Part 6: Bulk warrants Chapter 2: Bulk acquisition warrants Section 158: Power to issue bulk acquisition warrants
Subsection (1) sets out the power for the Secretary of State to issue a bulk acquisition warrant. A warrant may be issued only where it is necessary and proportionate for one or more specified statutory purposes. The interests of national security must always be one of those purposes. The decision to issue the warrant must be approved by a Judicial Commissioner. A warrant may only be issued to the three intelligence agencies.
	Subsection (1) also requires that the Secretary of State must consider that each of the operational purposes specified in the warrant is a purpose for which the examination of material obtained under the warrant is or may be necessary. Operational purposes limit the purposes for which data collected under a warrant can be selected for examination and no official is permitted to select data for examination other than as permitted by these purposes. Section 161 sets out more detail about operational purposes.
	This subsection makes clear that the operational purposes specified on a warrant must relate to one or more of the statutory grounds specified on the warrant. For example, if a bulk acquisition warrant is issued in the interests of national security and for the purpose of preventing and detecting serious crime, every operational purpose specified on that warrant must be necessary for one or both of these broader statutory grounds.
	Subsection (4) makes explicit that legitimate trade union activity would never be sufficient grounds, of itself, for a bulk acquisition warrant to be considered necessary.
	Subsection (6) sets out that a bulk acquisition warrant may authorise one or more of: requiring a telecommunications operator to disclose specified communications data in its possession or to obtain and disclose communications data which is not in its possession; the selection for examination of the data obtained under the warrant; and the disclosure of data described in the warrant.
	Subsection (7) provides that a bulk acquisition warrant also authorises conduct necessary to do what is required by the warrant.
	Subsection (8) provides that a bulk acquisition warrant may be issued in a relation to data which will come into existence in the future.