"Modern cell phones are not just another technological convenience.
With all they contain and all they may reveal, they hold for many
Americans 'the privacies of life. The fact that technology now allows an individual
to carry such information in his hand does not make the information any
less worthy of the protection for which the Founders fought. Our answer
to the question of what police must do before searching a cell phone
seized incident to an arrest is accordingly simple — get a warrant." Chief Justice John Roberts