Police Harassment occurs when:
Police Officers, being the mature adults that they aren't, usually victimize children or minorities, as they know they are the most likely to be ignored.
Bear in mind when you are being harassed: do not try to reason. Police officers have been trained in intimidation and escalation - they can make the situation as intense as is necessary to win, even if it means kicking the shit out of you. Get a name and a badge number, and fight back, and fight back hard.
Do be careful how you fight back, though, as cops tend to stick together. You get one in trouble, six get you in trouble. They can always find a reason to pull you over, waste your time, ticket you and even arrest you.
Not all cops are bad - but experience and study have taught me one thing: it's a safe bet that the next one you meet will be. So be careful.
See also: Zero Tolerance for Police Harassment: Summer 2000 South Haven, MI and Police Truck by the Dead Kennedys.
This was a nodeshell fix.