Passengers can be frisked by police, even if nothing indicates they commited a crime

WASHINGTON—The Supreme Court ruled Monday that police officers have leeway to frisk a passenger in a car stopped for a traffic violation even if nothing indicates the passenger has committed a crime or is about to do so.
The pat-down is allowed if the police "harbor reasonable suspicion that a person subjected to the frisk is armed, and therefore dangerous to the safety of the police and public," Justice Ruth Bader Ginsburg said.

Link: http://www.boston.com/news/nation/washington/articles/2009/01/26/us_supreme_court_says_passenger_can_be_frisked/