"The Supreme Court ruled on Monday that in making a routine traffic stop, the police can permit a trained dog to sniff the car for drugs without the need for any particular reason to suspect the driver of a narcotics violation." NY Times.
Because on most highways every single car is driving faster than the speed limit, this decision gives police the power to stop any car they feel like and then use a dog to sniff for drugs.
This decision seems to violate the spirit of the Fourth Amendment. Merely driving the same speed as everyone else should not give police probable cause to search you and your car for drugs.
Pete Guither predicts that "this ruling is likely to result in a massive increase in the use of drug-sniffing dogs."