Police spotting (junction watch)

If stopped ask the PC if the advice s/he is giving is their personal view or the law. If the former I would complain since it is not their role to give the public their own view on anything

Isn't it more likely that the advice being given is simply what they've been told to tell people?

I was surprised last night to find that what looked like every police van in London had converged on Russell Square. No one seemed interested in my lack of high-vis or helmet tho', am guessing the protest at ULU must've got a bit saucy.