An important document on how the British state deals with what it perceives as security threats:

“This significant, previously unpublished document (classified “RESTRICTED”, 2389 pages), is the UK military protocol for all security and counter-intelligence operations.

The document includes instructions on dealing with leaks, investigative journalists, Parliamentarians, foreign agents, terrorists & criminals, sexual entrapments in Russia and China, diplomatic pouches, allies, classified documents & codewords, compromising radio and audio emissions, computer hackers—and many other related issues.
The document, known in the services as the “JSP 440” (“Joint Services Protocol 440”), was referenced by the RAF Digby investigation team as the protocol justification for the monitoring of Wikileaks, as mentioned in “UK Ministry of Defence continually monitors WikiLeaks: eight reports into classified UK leaks, 29 Sep 2009.”

Read more at Wikileaks on UK protocols for dealing with security threats of all kinds, from investigative journalists looking for disclosure of official documents to Chinese officials seeking “influence” (there’s an extensive section describing Chinese intelligence gathering).