I would say this puts it a bit out of the comfort zone.
That's the problem with talking about a "right to privacy" in Anglo American law: there really isn't one. There are various protections serving different purposes, but they're not unified into some overarching principle of a right not to disclose or have information disclosed. That's why the subpoena power is so much broader than the power of police to search: because the animating principle isn't "privacy" but rather the protection of criminal defendants. If it were about privacy it wouldn't make sense to e.g. treat witnesses, who can be compelled to testify, differently than defendants, who can't.
Now, I'm not arguing that this is the best possible way to do things. But it's the way we have been doing it for centuries (since the Middle Ages).
As a general rule, there's "no money" in doing something like that. You run the risk of getting sanctioned, and if you use the information improperly in other litigation, it'll just get excluded as having been obtained via abuse of a subpoena.
The bigger worry is stuff like this, which doesn't happen under court supervision: http://www.wired.com/threatlevel/2012/08/administrative-subp....
But that's a very different issue than privacy rights in general.