Amicus brief in “Carpenter” Supreme Court Case[no description provided]
"In an amicus brief filed in the U.S. Supreme Court, leading technology experts represented by the Knight First Amendment Institute at Columbia University argue that the Fourth Amendment should be understood to prohibit the government from accessing location data tracked by cell phone providers — “cell site location information” — without a warrant."
For more, please see "In Supreme Court Brief, Technologists Warn Against Warrantless Access to Cell Phone Location Data." [Update: Susan Landau has a great blog post "Phones Move – and So Should the Law" in which she frames the issues at hand.]
I'm pleased to be one of the experts involved.