this debate is endless, and everybody is right and wrong on it.
some cops are bad, some are good. i choose to always exercise my rights every time, so long as i am guilt-free, no matter whether the cop is decent to me or a dick. i treat every cop that i meet as a reckless authority figure, until he proves me otherwise. of course, this still means that i treat ALL of them with due respect (ie they have a gun and badge). however, i trust none to have my best interests at heart, but I do still expect them to have my preservation at heart. thats all.
cautious, realistic, but never sleeping.
it also helps when you are not consistently breaking the laws, no matter how stupid they are. if you are doing something illegal, you have no recourse when you run across a tool cop. if you are in the right, you either wont get in trouble, or you take it to court and hope for the best.