A New York attorney who specializes in e-discovery has posted an article about the recent cell tower case from Texas at law.com.
The author believes that the court "reasoned incorrectly as to the application of the Fourth Amendment to cell tracking information" and " overlooked a basic point of Fourth Amendment jurisprudence."
For the author, the key point is that the cell phone company, and not the government, collects the tracking data. I think he is correct – up to a point. My evolving view is that the government acts outside of the Fourth Amendment in acquiring tracking data about a specific discrete period of time. However, when the government acquires a significant amount of data about a person's activities over an extended period of time, a distinct right to privacy is triggered and a warrant is required – even if the data is in the hands of a third party – like cell phone data – or publicly available – like GPS trackers.