Oh my..
There is a link at the bottom of that pdf, to another pdf..
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/426248/Acquisition_and_Disclosure_of_Communications_Data_Code_of_Practice_March_2015.pdf
There is a lot in there to be worried about, this for instance..
"2.7. Particular consideration must also be given, when pertinent, to the right to freedom of expression.[28]
[28] See the section on communications data involving certain professions, beginning at paragraph 3.72, for further information and guidance, including on the requirement for the use of the Police and Criminal Evidence Act 1984 until such time as there is specific legislation to provide judicial authorisation for applications for communications data to determine journalistic sources."
My emphasis in bold.
Journalistic sources are fair game apparently, along with everything else. IANAL and the guidelines are a bit wordy, but a lot of it can be interpreted in an 'abusive' way. Particularly the bit about stopping data interceptions when it relates to someone in a public office under particular circumstances - very shady looking notes.
Perhaps I'm just paranoid or I'm incorrectly parsing the information, but it basically says that they can use the RIPA for anything deemed a 'crime' or for anything they like really under a lot of pretext-type categories, and that it extends to anywhere in the world if it relates to a service supplied to someone in the UK. It even trumps the ECHR!