This Note begins by focusing on the technology and procedure of geofence warrants in Part I. Because an understanding of both the technology and procedure is ultimately required to make any headway in later legal analysis, this step is necessary. The heart of the legal analysis is undertaken in Parts II and III.
In Part II, this Note argues that law enforcement requests for location data require a warrant: either because of the expectation of privacy in location data proposed by cases such as Carpenter v. United States or because some courts have found that Carpenter's holding must mean location data should be treated as content, which triggers a statutory warrant requirement under the Stored Communications Act.
In Part III, having established a warrant is necessary, this Note further argues geofence warrants can satisfy the probable cause and particularity requirements of the Fourth Amendment. For probable cause, the government must narrowly tailor the warrant to objective, established facts, avoiding the incidental capture of other users as much as possible. For particularity, in a similar sense, the government must use ex antelimitations on the warrant that restrict the capture of data to only those individual users for whom probable cause has been established, permitting as little officer discretion in the execution of the warrant as possible. Courts view the Fourth Amendment through the lens of what is reasonable: a narrow geofence warrant is better, all things considered. To effectively tackle these complex Fourth Amendment issues, this Note begins with technology and procedure of a geofence warrant itself.
This abstract has been adapted from the author's introduction.