Prosecutors have been subpoenaing cell phone records for years now during investigations of vehicle fatalities.
Bail revoked for woman charged in Brimfield crash that killed young brothers
In May, defense lawyer Joan Williams asked to move the trial to October, citing the more than 5,000 pages of cellphone records provided by prosecutors, who allege Hardy was texting at the time of the crash. http://www.masslive.com/news/index.ssf/2016/07/bail_revoked_for_holland_woman.html
Woman Sentenced to Prison in Fatal Distracted Driving Crash http://www.nbclosangeles.com/news/local/Woman-Sentenced-to-Prison-in-Fatal-Distracted-Driving-Crash--324442181.html
Driver Using Cellphone Convicted of Vehicular Manslaughter By Mike Doyle Aug. 13, 2015
http://www.kdrv.com/news/Driver_Using_Cellphone_Convicted_of_Vehicular_Manslaughter.html
Massachusetts teen convicted of homicide in texting-while-driving case
By the CNN Wire Staff
http://www.cnn.com/2012/06/06/justice/massachusetts-texting-trial/
Yes, but what about watching a movie or reading email that has already been downloaded? I believe the scofflaws will always be one step ahead of the law as technology changes so fast.