Tbh there is a limit to what they can do at least in EU, especially in countries like France or Germany where data privacy laws are extremely strict. When I worked in computer forensics for a multinational it was nigh impossible to gather evidence from those areas. I don't know about UK but they likely will have only access to some top level information but won't be able to drill down into what you write or post, not without additional authorization if any exists, anyway.
For example some security scanners used to support investigatrions into phishing incidents may tell you what the users clicked and what actions they took in say, Outlook, but not the contents of what they write or in some cases not even the titles of emails and such.
