On October 16, 2014, Florida Supreme Court ruled that police need a warrant to access your cell tower data. The case is Shawn Alvin Tracey vs. State of Florida.
…We begin with one of the bedrock principles of our federal constitution, the Fourth Amendment to the United States Constitution, which states:
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
Amend IV, U.S. Const.
Over four decades ago, the Supreme Court emphasized the importance of fidelity to the foundational premise of the Fourth Amendment in Coolidge v. New Hampshire, 403 U.S. 443 (1971), stating:
[T]he most basic constitutional rule in this area is that “searches conducted outside the judicial process, without prior approval by judge or magistrate, are per se unreasonable under the Fourth Amendment—subject only to a few specifically established and well-delineated exceptions.” The exceptions are “jealously and carefully drawn,” and there must be “a showing by those who seek exemption that the exigencies of the situation made that course imperative.” “[T]he burden is on those seeking the exemption to show the need for it.” In times of unrest, whether caused by crime or racial conflict or fear of internal subversion, this basic law and the values that it represents may appear unrealistic or “extravagant” to some. But the values were those of the authors of our fundamental constitutional concepts. In times not altogether unlike our own they won—by legal and constitutional means in England, and by revolution on this continent—a right of personal security against arbitrary intrusions by official power. If times have changed, reducing everyman’s scope to do as he pleases in an urban and industrial world, the changes have made the values served by the Fourth Amendment more, not less, important.
Id. at 454-55 (plurality opinion) (footnotes omitted). Although these words were penned long ago, they have proved prescient now that technology has advanced to the point that our whereabouts can be ascertained easily and at low cost by the government. As the Supreme Court wisely cautioned in Coolidge, “[i]f times have changed,” such as they have now that technology has provided the government with technological capabilities scarcely imagined four decades ago, the protections of the Fourth Amendment are “more, not less, important.”
…Fourth Amendment violation occurs when government officers violate a person’s “actual (subjective) expectation of privacy” that “society is prepared to recognize as ‘reasonable.’ “
Read the full ruling here
U.S. Constitution, Amendment IV states:
“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”
Florida Constitution, Artilce 1, Section 12 – Searches and Siezures states:
“The right of the people to be secure in their persons, houses, papers and effects against unreasonable searches and seizures, and against the unreasonable interception of private communications by any means, shall not be violated. No warrant shall be issued except upon probable cause, supported by affidavit, particularly describing the place or places to be searched, the person or persons, thing or things to be seized, the communication to be intercepted, and the nature of evidence to be obtained. This right shall be construed in conformity with the 4th Amendment to the United States Constitution, as interpreted by the United States Supreme Court. Articles or information obtained in violation of this right shall not be admissible in evidence if such articles or information would be inadmissible under decisions of the United States Supreme Court construing the 4th Amendment to the United States Constitution.”