Never say anything to cops. I've had this happen to me based on stuff my friends have said on twitter/facebook. Say nothing.

Record them if you want, but do not speak at all. Also, they are under no obligation to follow rules or any ideals. They're paid enforcers of everything evil and they will not get into trouble for breaking rules. They can do anything they want. You can't. Best option is to be quiet and don't give them anything to work with.

Don't let them inside your home or look through your things without a warrant. Do not agree to searches. Don't be like a sovereign citizen, that "am I being detained" stuff doesn't work and the cops don't care.