Long-term cell phone tracking warrants require probable cause, but good faith applies here. “[W]hen the government requests authorization to engage in long-term, real-time tracking of an individual’s movements via his or her cell phone, the situation reaches past the law set forth in Skinner, and Fourth Amendment concerns are implicated.” The court analyzes nearly all the cases to date. United States v. Powell, 943 F. Supp. 2d 759 (E.D. Mich. 2013) (not on court’s website):
3. Probable Cause Showing for Real-Time Cell-Phone Tracking
In the absence of a definitive statutory niche for prospective cell-phone tracking, and in light of the considerable, and distinctive, privacy concerns raised by long-term, real-time cell-site tracking discussed above, scrutiny of the appropriate probable-cause showing in these cases is called for. The Court concludes that a specific showing is required to establish probable cause when the government seeks a warrant for long-term real-time tracking of an individual via a cell phone. Such a showing should include facts supporting, at least, the following:
First, that the actual location of the person the government intends to track via the cell phone is relevant to the investigation of the ongoing crime, or evidence sought. That is, if the government intends to track an individual over a long period of time, and cannot show that the individual will be, for example, in public, non-protected locations for the duration of the tracking, then the warrant application should set forth facts that warrant intrusion into protected locations that the individual may frequent. In other words, the government should set forth a probable-cause basis for following the individual into protected areas via the individual’s personal cell phone.
It is true that, in a sense, a person’s location is in some way always relevant to his potential participation in a crime. And, a person does not have a general privacy interest in his location. But before the government may use an individual’s cell phone to track him into areas in which an individual does have a reasonable expectation of privacy, the government should show more than that the person is suspected of a crime; the government should show that the person’s location in the protected area is in some way relevant to the ongoing investigation of criminal activity. See generally United States v. Frazier, 423 F.3d 526, 532 (6th Cir. 2005) (“The critical element in a reasonable search is not that the owner of property is suspected of crime but that there is reasonable cause to believe that the specific ‘things’ to be searched for and seized are located on the property to which entry is sought”).
Second, the government should show that the specific cell phone, as well as the person to be tracked, is relevant to the investigation. That is, the government must show there is a nexus between the cell phone, the suspect, and the information sought. See generally United States v. Carpenter, 360 F.3d 591, 594 (6th Cir. 2004) (warrant application must show “a nexus between the place to be searched and the evidence to be sought”); see also, e.g., United States v. Sierra-Rodriguez, 10-20338, 2012 U.S. Dist. LEXIS 50411, 2012 WL 1199599, at *6 (E.D. Mich. Apr. 10, 2012) (finding probable cause shown where the affidavit provided substantial basis to conclude that specific cell phone tracked belonged to suspect embarking on criminally-related travel). This means that the government should show that a criminal suspect under investigation is the likely user of the cell phone at issue and that he or she uses the cell phone in connection with criminal activity. Investigation of a criminal organization using multiple phones, including dedicated phones for criminal activity, over the course of the operation would require the government to make a showing as to each phone it intends to track. The logic of this requirement is simply that, drawing on the Fourth Amendment’s particularity requirement, tracking a phone used in furtherance of criminal activity is likely to lead to evidence of criminal activity, whereas tracking phones, the use of which is unconnected to criminal activity, will likely demonstrate where a person conducts highly personal business.
In sum, because “the belief that the items sought will be found at the location to be searched must be supported by less than prima facie proof but more than mere suspicion,” to establish probable cause for long-term, real-time, cell-site tracking, the government should have to demonstrate a nexus between a suspect and the phone, the phone and the criminal activity, as well as the criminal activity and suspect’s location in protected areas, rather than merely probable cause that the person is engaged in criminal activity. See generally United States v. Williams, 544 F.3d 683, 686 (6th Cir. 2008).
This standard obviously does not deal a serious blow to the government’s ability to obtain real-time cell-site location data. Although specific, the showings required are nowhere near as stringent as those for a Title III wiretap, which require agents to state that “normal investigative procedures have been tried and failed or reasonably appear to be unlikely to succeed if tried or to be too dangerous” by including “a full and complete statement as to whether or not other investigative procedures have been tried and failed or why they reasonably appear to be unlikely to succeed if tried or to be too dangerous.” United States v. Poulsen, 655 F.3d 492, 503 (6th Cir. 2011), reh’g denied (Oct. 17, 2011), cert. denied, 132 S. Ct. 1772, 182 L. Ed. 2d 533 (2012) (quoting United States v. Rice, 478 F.3d 704, 716 (6th Cir. 2007)). The showing described here does not require exhaustion of other investigative techniques; it simply calls for the government to provide additional facts in its warrant application to justify tracking an individual via his personal cell phone, over an extended period of time, into protected spaces. The result is a showing that is not necessarily heightened, rather it is simply responsive to the full range of recognized privacy interests at stake in long-term cell-phone tracking.
However, the good faith exception applies:
Defendants argue that the exception does not apply here because the affidavit is lacking in indicia of probable cause, such that the DEA’s reliance on it was objectively unreasonable. An affidavit is lacking in indicia of probable cause, also known as a “bare bones” affidavit, if it contains only “suspicions, beliefs, or conclusions, without providing some underlying factual circumstances regarding veracity, reliability, and basis of knowledge.” United States v. Laughton, 409 F.3d 744, 748-49 (6th Cir. 2005) (quoting United States v. Weaver, 99 F.3d 1372, 1378 (6th Cir. 1996)). This standard is “a less demanding showing than the ‘substantial basis’ threshold required to prove the existence of probable cause in the first place.” Id. (quoting Carpenter, 360 F.3d at 595). The Court has already found that the affidavit met the substantial-basis threshold; it necessarily was also not lacking in indicia of probable cause. Accordingly, the good-faith exception applies. The evidence obtained pursuant to the March 11, 2010 warrant for real-time cell-site location data is admissible and will not be suppressed.

