I wouldn't say that either the UK or the USA have hit the Police State yet. Inching closer, yes, but i've yet to hear anything about arrests in the middle of the night, or clandestine government agencies abducting it's own citizens. Spying on its populace does set a bad precedence, especially when the agencies responsible have been so determined to keep it hidden, but it's not, in my mind, past the totalitarian threshold yet.
As for what can be done... Well, don't rely on the Queen. As much as i think the old lass could do a better job than either yours, or my parliament, something like that simply isn't done anymore, legal precedence or not.
I also don't think the growing cry (mostly in the States, admitedly) for armed revolt is an answer. Truth be told, i haven't been able to find a single revolution which actually created a better system than the one it was against. That type of change happens over time, with the hard work of forward thinking people who are willing to work with the system to bring about those changes.
So, to that end, i would say the only way to do something about it is to educate yourself. Get involved in politics and the ethics of freedom. Get other people involved. An educated and engaged population is alot harder to manipulate than a bunch of blind sheep, and the only way you can prevent breaches of civil trust like this is if people are actually paying attention.