Whether police officers have reasonable suspicion under the Fourth Amendment to initiate a traffic stop for briefly holding a cellphone

QUESTION PRESENTED More than 20 states have laws that prohibit sending text messages on a cellphone while driving, but allow drivers to use their cellphones for other purposes, such as navigation or playing music. The question presented is: Whether police officers in those states have reasonable suspicion under the Fourth Amendment to initiate an investigatory traffic stop, where they observe a driver briefly holding and manipulating a cellphone, in a manner that does not indicate whether the cellphone is being used for a lawful or prohibited purpose. (D