I can see a 'fudge' coming on:
activities exclusively for the purposes of market research;
activities exclusively concerned with a credit check;
professional activities of practising solicitors and Barristers;
professional activities of practising accountants;
professional activities of journalists and broadcasters, and activities exclusively relating to obtaining information for journalists and broadcasters;
activities exclusively relating to reference to registers which are open to the public; registers or records to which a person has a right of access; and published works;
activities carried out with the knowledge or consent of the subject of the investigation.
With a little poetic licence, there's a lot of wriggle room. I know quite a few 'PI's', that can't be arsed with SIA, contemplating 'retirement'. They'll just disappear under the radar, and become 'researchers / consultants'.
As anyone can call themselves a 'freelance journalist', and justify it by maintaining an intermittent blog on an obscure news site, how the hell can any 'authority' police the difference between the two ?
V