If you have not been charged with a crime, can you just refuse to hand over your cards?
If they're so inclined they can take your things by force and you will have no reasonable means of recourse.
It's like being charged solely with resisting arrest.
http://www.thedailybeast.com/articles/2014/08/15/the-day-fer...
The truth of the matter is that people are barely evolved ape/chimps and do pretty much whatever suites them as long as they don't get their ass kicked for it.