Professor Jay Kesan was the featured guest on the December 11, 2017 episode of Illinois Public Media's Legal Issues in the News. 

"When you make or receive a phone call or text message with your cellular phone, your service provider stores information about which cell tower transmitted this signal, thus revealing the general area where you were located when that transmission occurred.  

"Courts have been disagreeing for years about whether this historic cell-site location data gathered by your cellphone service provider can be obtained without a warrant. On November 29th, the U.S. Supreme Court heard oral arguments in U.S. v. Timothy Carpenter to resolve this issue. That case involved a string of robberies. The defendant’s physical proximity to the robberies, as shown by cell site data, was used as circumstantial evidence against him. Should the police have obtained a warrant before they collected information about the whereabouts of Mr. Carpenter’s phone and by extension, Mr. Carpenter himself?"

Listen to the full episode.