“The [nuclear industry funded] force is authorised to send informers to infiltrate organisations and to conduct undercover surveillance under the Regulation of Investigatory Powers Act 2000 (RIPA). It is also permitted to obtain communications data such as phone numbers and email addresses.” ~ The Guardian
Although this was first published in 2009, it would be extremely naive to think that the situation has changed since then. Just bear it in mind.
Read the full article from the Guardian.