Excellent post by a blogger I've newly discovered:

The term “police state” is not a well-defined one, but I think most people would agree that such regimes are characterized by extensive surveillance of the population; a huge number of arbitrary laws punishable by disproportionate penalties; a slow and arbitrary court system in which the outcome of important cases is essentially pre-ordained; a requirement that ordinary citizens carry identity documents everywhere and present them to officials on demand (“papers, please!”); a bloated police force whose powers are limited only by the imaginations of officials and whose members are able to inflict violence upon anyone they choose without any consequences whatsoever or recourse of any kind for the victims; and a powerful bureaucracy which regularly violates the laws which supposedly constrain it and ignores due process when it proves inconvenient. For good measure, let’s throw in worshipful reverence of officials and a media which largely parrots every press release those officials come out with, and I think you’d be hard-pressed to come up with some way in which the US isn’t a police state.

Their last July 4th post is great too.