Goodness me, handbags at dawn or what? I have no close knowledge of West Yorks ASU policy or of this case, [though the prose style of MD600 and sbiggee do seem remarkably similar?] but let me offer my view.
Our ASU takes photos all the time; contingency planning, accident investigation and frequently for prosecution cases. Pretty much without exception the requests for the photos/video come from an agency external to the ASU and they have to go through various levels of authorisation and approval depending on the subject.
We obviously note where someone may have a private landing site; I'm sure you'd want the police crew in your area to know when to be alert to someone rotors running in a back garden about to lift? Only once in 14 years have I been tasked to take photos for a case involving aviation legislation and that was at the CAA's request.
Basically what I'm offering is an answer to a point that crops up maybe every 6 months on this forum; police ASUs are extremely unlikely to instigate a prosecution against another pilot unless what's been done is absolutely outrageous; to be honest it causes more problems than it solves, and the quiet phone call should be the preferred option in wherever possible. If, however, we perform the role of, er, Air "Support" Unit then we can be tasked to support another part of the force whether we like it, agree with it or aren't even remotely a**ed one way or the other by providing a service to meet their request.
This isn't being slopey-shouldered, just following orders, but to suggest that someone is conducting some sort of malicious harrassment without the other side being put is really a bit much.