Originally Posted by Fletch XXX

It depends on which state, of course California has fought it, but in Nevada it is grounds for arrest.

http://www.seattlepi.com/local/418803_videoside.html

"in 2004, the U.S. Supreme Court upheld a Nevada law that says cops can bust you for withholding an ID, if they have reasonable suspicion you were involved in a crime."

It falls under "stop and identify" laws.