> [ ... ] what about 'police state'? I have only ever visited
> the US once in my life, but I never heard so many sirens
> before as I did there.
I don't know where you visited, but in most big US cities Fire/EMS calls outnumber significant police calls by something like a factor of 5. Almost every callout for them is a "code 3" response -- full lights and sirens -- because it's usually a matter of someone's well-being at stake. On the other hand, the vast majority of police call outs are not with such urgency, and thus would be made without running the siren. Why do "firemen" spend so much of their time on medical calls? I think we all know the reason for that: regular preventative care would remove the necessity for many 'emergencies' that get handled by the fire department.
You were most likely hearing fire engines, not police cars.
/jordan