Yes, I've seen one stopped at a DWI checkpoint, and refuse to answer whether he had been drinking that night. I've seen people refuse to give their license and registration. I saw a woman who refused to pull her vehicle over to secondary when the officer asked. It's quite educational. They are all white, btw.
There are some constitutional issues with warrantless checkpoints, and police are not allowed to take your indentification without a reasonable, articulable suspicion of a crime.
Nor are you required to answer any of their questions.
I don't mind complying, within reason, but I'm glad that there are people reminding them that they are not legally permitted to demand such things.
Those guys are fighting for all of us, and are risking jail or worse to make that point. Freedoms are lost a little at a time, and it's good to exercise them every now and then just to keep them healthy.