A "routine traffic stop" is a term used by law enforcement officials to refer to pulling over a vehicle when it is believed that a crime has occurred, even if it is only a minor traffic law violation or infraction. Examples of a routine traffic stop include a police officer pulling over a vehicle for speeding, for following another vehicle too closely, for having illegally tinted windows, or for having a nonworking headlight and taillight. The phrase "routine traffic stop" is also widely used in the media to describe how police officers ultimately find drugs, weapons, or other contraband when they initially pull over a vehicle for a minor traffic violation. Additionally, courts use the term "routine traffic stop" to describe constitutionally permissible and impermissible law enforcement activities in disputed cases. For instance, the United States Supreme Court has held that using a drug-sniffing dog during a "routine traffic stop" does not violate the 4th Amendment to the U.S. Constitution.