Pretty sure there's been a recent case [which, inevitably, I can't presently track down via google] on Data Protection and disclosure in libel actions when the owners of a website refused to disclose the name of the originator of the alleged libel. It was held that the Act was to protect the individual not the website owner. If that individual published a libel via the website, it was no answer for him to claim that his rights under the Act were infringed by his identity being disclosed to the person libelled, for otherwise the most libellous lies would be published with impunity.It followed that the website could not resist an application for disclosure, a pleadable cause of action for libel being shown.
Even in the absence of suitable binding authority, the argument appears sound common, and legal, sense.