Earlier quoted context omitted.
Europe has similar stories of being horrible in spots too, look at french jails for example: http://www.newsweek.com/french-prisons-are-becoming-embarras...
Thanks for the link, really interesting/enlightening read. I would hope, at least, that Europe's police officers are on the whole less pointlessly violent (though, as Peretz points out the majority of SF police probably don't act as such).
Japan for another example has scary high conviction rates, even though it's a very safe country where police will probably never harass you. Once a prosecutor there goes ahead with a trial, your pretty much guaranteed to be going to jail.
I'm not trying to be morally relativistic here and saying your screwed everywhere, but law enforcement systems show this systemic flaw in their organizations in general. How much they control the bad behaviors is up to the culture and design of the incentives. The better designed ones will have a much better probability of not screwing you over. But most people, including unexposed Americans, don't realize the unjust nastiness of law enforcement gone bad and think police are a good thing in developed nations, just like you do in europe.