Comment by AlecSchueler

> So you're saying it's still at the discretion of a single magistrate?

A judge isn't a magistrate, but also: No, of course not. There are different layers of legal protections in the UK. You would be able to appeal the notice itself, you would be able to argue at the court against the decision, and you could make an appeal to a higher court if your were convicted. Furthermore you could make an official complaint about the investigation afterwards.