Here in MI having a mm card is considered an "affirmative defense" to a possession charge. This means if prosecuted you can use this to prove your innocence.

I've heard that some cops will still arrest people despite them having the card just because they don't agree with the new law.

That is some seriously messed up shit. Why do they even care so much? I don't know why they even feel they have a dog in the fight. Why does one man care if another wants to smoke a bowl after a day of work?

Anyway, I'm sure the law suits will fly and this crap will stop.