On Aug. 14, 2012, the U.S. Court of Appeals for the Sixth Circuit issued the opinion in United States vs. Skinner (1). In Skinner, federal Drug Enforcement Administration agents seized data maintained by a cell phone service provider in an effort to derive as closely as possible the real-time geographical information residing on defendant Melvin Skinner’s “pay-as-you-go” mobile phone (2). The “cell tower” data was subsequently used to establish Skinner’s location as he transported drugs interstate on public roadways. DEA agents tracked the cell phone they learned was associated

with Skinner, locating the device’s signal at a rest stop. Soon thereafter, law enforcement officials encountered a motorhome filled with over 1,100 pounds of marijuana. After litigating the merits of the seizure at some length, the trial court denied Skinner’s motion to suppress the government’s search of the motorhome, eventually resulting in a conviction for drug trafficking and conspiracy to commit money laundering (3).

 Cell Site Location Data

 The court of appeals held, inter alia, that Skinner did not have a reasonable expectation of privacy in the geo-location data produced by the mobile phone that became available to law enforcement officials from the cell phone carrier’s network (4) Skinner is a good example of how legal precedent, although ever-evolving, is not   necessarily progressing in lock step with technology and the realities of the ways in which it is being embraced by modern society. In other words, as technology changes, arguably so should the manner in which courts across the United States apply the two-factor “subjective/objective” test expounded by the U.S. Supreme Court in Katz v. United States (5).

 The Sixth Circuit draws a distinction between Skinner and United States v. Jones (6).    In Jones, the U.S. Supreme Court held that the government’s installation of a GPS device on the defendant’s vehicle in order to “track” it constituted a “search” in violation of the Warrant Clause in the Fourth Amendment (7).  Jones, a significant coup for the criminal defense bar, recognizes that society has adopted a reasonable expectation of privacy as to travel inside a motor vehicle.

 The subjectivity prong of Katz is not so clear-cut when it comes to cell use location evidence. For example, in Commonwealth v. Pitt, a Massachusetts Superior Court ruled cell location evidence to be the type of information society is ready to adopt as being private under the Fourth Amendment because individuals do not expect their whereabouts to be logged simply because of the phone calls they make (8). Ironically, it appears the Sixth Circuit perceived the defendant’s use of a prepaid or “pay-as-you-go” cell phone as evidence of defendant’s subjective intent not to be followed.

 While Jones involved intensive monitoring over a 28-day period, in Skinner the court found that the DEA agents only tracked Skinner’s cell phone for three days. The court justified the result in Skinner by raising, among other issues, the question of whether monitoring a vehicle carrying contraband across interstate highways is not  overly invasive if less expensive and more efficient means to do so are available to law enforcement (9). Arguably, if one adopts Skinner then Jones would provide — which it does not— that individuals could be tracked by GPS without a warrant so long as they have GPS in the car being tracked.

 Pinging Technology

 In most cases, cell site location data used to establish a defendant as the “perpetrator” of a crime begins with “pinging”(10). A “ping” typically refers to a cell phone connecting with the closest cell phone tower because someone placed a call though that cell phone. The phone then makes contact with the closest cell site (i.e., “tower”), and the call is then transmitted to the receiving tower (11). Trial courts, including those in the Sixth Circuit, are certainly familiar with the concept that if “a  cell phone  is ‘on’ (regardless of whether the phone is then making or receiving a phone call or text message), the phone automatically and periodically transmits a signal to ‘register’ with the cellular network” (12).

 Skinner recognizes that pinging technology is routinely used by law enforcement to investigate and track suspects without the use of a search warrant (13). Criminal defenders across the country are likely routinely encountering this tactic, which invites the question presented by  Katz  v. United  States in 1967: How far does the Fourth Amendment’s protection reach? (14). Unfortunately, the answer is “not too far” if one adopts Skinner wholesale without taking several factors into consideration.

 Mobile communications are inextricably tied to daily personal and business activities. Traditional notions of what society may consider as an expansion of private conduct are being redefined. Cell phones and “home” phones are becoming unified by virtue of technological advancements (15). Notably, Katz established that the Fourth Amendment protects people and not places, which is another reason to progressively apply its holding to the mining of mobile data collected by law enforcement.

 Expectations of Privacy

 The concept of a right to privacy in one’s “curtilage” is different than it was over 25 years ago (16). Like technology, both subjective and objective notions of privacy are evolving. Cell phone data should not be deprived of Fourth Amendment protection due to its mobile characteristics. Skinner does not appear to appreciate the notion that society’s mainstream sense of “privacy” is no longer based on defined locations or “places,” and there- fore, curtilage has become, in many ways, “virtual” with respect to electronically stored information. Therefore, factors concerning whether such  data  may be seized without  a  search  warrant  must continue to evolve (17).

 Skinner relies upon the suspect tracking case of United States v. Knotts in which the U.S. Supreme Court found no inherent constitutional difference between trailing a defendant and tracking him by means of a “beeper” (18).  The finding in Knotts is substantially attributed to the Court’s holding in Smith v. Maryland, the case establishing that a subscriber telephone service has no reasonable expectation of  privacy in the numbers he or she dials through a carrier’s switching equipment (19).  However, cell phones are not landlines, which is why other courts have since held that “[a] cell phone subscriber does not use the phone to track his own movements in real time, [and therefore,] prospective cell site data appears to be unrelated to any customer (as opposed to law enforcement) use of the provider’s services” (20).

 Individuals have a reasonable expectation of privacy in their mobile devices. This privacy expectation is evidenced by the security features they choose to enable or disable (21). This concept was applied to wireless Internet access in United States v. Ahrndt. In Ahrndt, federal agents accessed the defendant’s home Wi- Fi network through a wireless router used to file share child pornography through the iTunes  software application (22). The government was able to associate the IP address of the router with the defendant. Since the wireless router was not password protected, the data transmitted across the network was not “private,” and therefore, the defendant’s motion to sup- press was denied. A reasonable argument can be made that the law may differentiate between end-users who display a subjective expectation of privacy in their technology by how it is used, and end- users who opt into being “tracked” by cell phone service providers and/or other third-party services (23 ). Given the extent of the permission cell phone location service providers seek from their end-users, it is clear that members of society have an expectation of privacy in not only the content on their cell phones, but also their locations.

 Specifically, a recent survey found 31.6 percent of American households are “wireless only” (i.e., no traditional land- line telephone service inside the home) (24). The physical location of a mobile telephone is in many ways an extension of an individual’s own person. Consider United States v. Karo, holding that once an individual targeted by the government enters the threshold of the doorway into the home, the surveillance of the location of the handheld without a warrant arguably becomes unconstitutional (25). Katz reinforced the principle that the Fourth Amendment to the U.S. Constitution “protects people, not places” (26). Therefore, the analysis of mobile data should begin with the associated case-specific conduct being analyzed in order to determine the actual or subjective expectation of privacy the person challenging the seizure exhibited. The analysis then turns to the circumstances under which society as a whole views the expectation of privacy as reasonable and objectively acceptable (27).

Cell phones, whether under contract or prepaid, are not purchased with the expectation that the government will have unfettered access in order to mine through the geo-location data created through use of the phone. Therefore, Skinner is arguably inconsistent with the Supreme Court precedent established in Kyllo v. United States (28). The government may not conduct unreasonable searches, even with technology that does not physically enter the home such as thermal imaging of a defendant’s residence, which was found to constitute a search subject to Fourth Amendment scrutiny (29).  The Court reasoned that the device used by law enforcement was not readily available to the public, and therefore, the search was unreasonable under the Fourth Amendment and therefore unconstitutional (30).

 In Kyllo, the Court’s “firm but also bright” line drawn by the Fourth Amendment at the “entrance to the house” is arguably not sufficient in the context of mining prospective cell phone geo-location (31). Skinner risks blurring the distinction be- tween permissible seizures pursuant to the Communications Assistance for Law Enforcement Act (32) and data to which law enforcement should not be permitted access such as real-time or prospective geo-location data (33). Mining for real-time or prospective geographical coordinates of usage is not a method of observation available to members of the public — unlike a camera used for aerial mapping (34).

Skinner appears to stretch Knotts too far. Civilians can place a tracking device in a vehicle provided there is lawful access, but cannot access cell phone geo-location data like law enforcement  — absent extraordinary circumstances recognized by court order (35).  In addition, the average person requires a licensed soft- ware application to track a mobile phone as opposed to Web-based “pinging” access provided to police by the cell phone net- works. Therefore, the location where the numbers were dialed from or the location from where calls were received should be deemed private as is any other content relating to a mobile phone that is generally protected (36).

 Revising the Fourth Amendment’s Scope

 Societal use of mobile technology may appear to be less “private” due to the nature and frequency of its use outside of the “physical home” and beyond one’s tangible “curtilage” (37).  Therefore, cell phone location data is a byproduct produced by the technology itself, and using it should not be considered providing de facto consent to a search.

 The Supreme Court in a separate concurring opinion in United States v. Jones noted  that GPS tracking without physical intrusion may trigger Fourth Amendment scrutiny (38). The Court did not reach the question in Jones, but when opinions like Skinner appear to be in conflict with those like Kyllo, the opportunity for the Court to expand the scope of the Fourth Amendment protection in the context of cell towers, and maybe even the Cloud, might be just around the corner (39).

 Notes

1. United States v. Skinner, 09-6497, 2012

WL 3289801 (6th Cir. Aug. 14, 2012).

2. Id.

3. Id. at *3 (“Skinner was charged  with conspiracy  to distribute  and  possess  with intent  to distribute  in excess of 1,000 kilo- grams of marijuana, in violation of 21 U.S.C. §§ 846, 841(a)(1), and 841(b)(1)(A), conspiracy to commit money laundering, in violation of 18 U.S.C. § 1956(h), and aiding and abetting the attempt to distribute in excess of 100 kilograms of marijuana, in violation of 21 U.S.C. §§ 846, 841(a)(1), 841(b)(1)(B), and 18 U.S.C. § 2.”).

4. Id.

5. See Katz v. United States, 389 U.S. 347 (1967) (the two-factor analysis is (1) whether a defendant has displayed conduct consistent with a subjective expectation of privacy; and (2) whether  such  subjective  expectation is one that society, objectively, is willing to find reasonable to the point it would be adopted).

6. United States v. Jones, 132 S. Ct. 945, 181 L. Ed. 2d 911 (2012).

7. Id. at 949.

8. See Commonwealth v. Pitt, 29 Mass. L. Rep. 445, *12-13 (Mass. Super. Ct. 2012):

The reasoning in Justice Alito’s concurrence is particularly applicable here. Just as society’s expectation has long  been that  law enforcement  would not  — could not  — precisely track the movements of a subject  of a  police  investigation over a protracted period, so too has society long expected that it would be impossible to reach into the archives  of a  person’s telephone service records and determine his location  at  prior  points  in  time, even when he was not the target of an investigation.

9. United States v. Skinner, 09-6497, 2012 WL 3289801 (6th Cir. Aug. 14, 2012).

10. Obama Administration Urges Freer Access  to  Cellphone  Records  ( Thomson Reuters)   (May  3,   2012)   available   at h t t p : / / w w w . r e u t e r s . c o m / a r t i c l e / 2012/05/03/usa-security-surveillance- idUSL1E8G3OL320120503 (last visited September 3, 2012).

11.  See  In  re  United  States  Orders Pursuant to 18 U.S.C. 2703(d), 509 F. Supp. 2d

76, 81 (D. Mass. 2007); In re Application of United States for an Order for Disclosure of Telecomm. Records, 405 F. Supp. 2d 435, 449 (S.D.N.Y. 2005).

12. See In re Application of the U.S. for an Order Authorizing the Disclosure of Cell Site Location  Info.,  6:08-6030M-REW,  2009  WL 8231744 (E.D. Ky. Apr. 17, 2009).

13. United States v. Skinner, 09-6497, 2012 WL  3289801 (6th Cir. Aug. 14, 2012) citing United States v. Jones, 132 S. Ct. at 964 (2012) (Alito, J., concurring)  (citing United States v. Knotts, 460 U.S. 276, 281-82 (1983)).

14. See In re United States Orders Pursuant to 18 U.S.C. 2703(d),  509 F. Supp. 2d at 81 (D. Mass. 2007).

15.  See  CITA, The Wireless Association®, Wireless Quick Facts: Mid-Year Figures (avail- able at  http://www.ctia.org/advocacy/ research/index.cfm/aid/10323).

16. United States v. Dunn, 480 U.S. 294,

300-301 (U.S. 1987) (“curtilage” is the immediate, enclosed  area  surrounding a house  or dwelling).

17. See the comments and content on the  pending Geolocational Privacy and Surveillance Act  (http://thomas.loc.gov/cgi- bin/bdquery/z?d112:h.r.2168).

18. United States v. Knotts, 460 U.S. 276 (1983).

19. Smith v. Maryland, 442 U.S. 735, 744-745, 99 S. Ct. 2577, 61 L. Ed. 2d 220 (1979).

20. See In re Pen Register &  Trap/Trace Device  With  Cell Site  Location Auth., 396  F. Supp. 2d 747, 759 (S.D. Tex. 2005).

 21. See Commonwealth v. Pitt, 29 Mass. L. Rep. 445, *12-13 (Mass. Super. Ct. 2012).

22. United States  v. Ahrndt,  2010  WL373994, slip op. (D. Or. January 28, 2010).

23. See In re Pen Register &  Trap/Trace Device  With  Cell Site  Location Auth., 396  F. Supp. 2d 747, 759 (S.D. Tex. 2005); Commonwealth v. Pitt, 29 Mass. L. Rep. 445,

*12-13 (Mass. Super. Ct. 2012).

24. Id.

25. See United States v. Karo, 468 U.S. 705, 715, 104 S. Ct. 3296, 82 L. Ed. 2d 530 (1984) (warrantless use of a beeper to monitor can of ether was an unlawful search; however, the Court upheld the conviction by finding affidavit in support of the  search  warrant  had enough information  not  derived  from  the unlawful use of the beeper for sufficient basis to find probable  cause, thereby  distinguishing the  unlawful monitoring  of beeper  signals to disclose information  about  a private residence from information that could other- wise be obtained from public observation).

26. Katz v. United States, 389 U.S. 347 (1967) (Harlan, J., concurring).

27. Id.

28. Kyllo v. United States, 533 U.S. 27, 40 (2001).

29. Id.

30. Id.

31. Id.

32. See 47 U.S.C. §§ 229, 1001 et seq.

33. See Brief for Electronic Frontier Foundation   and  Center  for Democracy  & Technology  as  Amici Curiae  Supporting Defendant  Antoine Jones’ Motion to Suppress  Cell Site  Data, United States v. Antoine Jones, 1:05-cr-00386-ESH (Document 644) (August 13, 2012) (D.D.C.).

34. See Dow Chemical Co. v. United States, 476 U.S. 227 (1986) (finding a “knowing expo- sure” exception to the warrant  requirement where federal agents  utilized an aerial map- ping  camera  to  enhance that  which  the human  eye could not observe from a lawful vantage point without trespassing).

35. See Electronic Frontier Foundation, CALEA  FAQ,  available at  https://www.eff. org/pages/calea-faq#1 (“The U.S. Congress passed the Communications  Assistance for Law  Enforcement  Act (CALEA) in 1994 to aid law enforcement in its effort to conduct surveillance of digital telephone networks. CALEA forced telephone companies to redesign their network architectures to make such surveillance easier. It expressly excluded the  regulation  of data  traveling over the Internet.”).

36. See 18 U.S.C. §§ 2510-22 (Wiretap Statute); 18  U.S.C.  §§  2701-12  (Electronic Communications   Privacy  Act);   18  U.S.C. §§  2701-12  (Stored  Communications   Act); and 18 U.S.C. §§ 3121-27 (Pen/Trap Statute).

37. See United States v. Dunn, 480 U.S. 294,

300-301 (1987).

38. United States v. Jones, 132 S. Ct. 945, 181 L. Ed. 2d 911 (2012) (Sotomayor, J., concurring).

39. See Kyllo v. United States, 533 U.S. 27, 40 (2001).