I. Introduction
Wearable technology compiles extensive information on our bodily systems—including activity levels, menstruation and fertility, exercise activity and attainment, food consumption, weight, sleep, noise exposure, heart rate, skin temperature, and respiratory rate. These devices can compile data on location using GPS functionality. They can even measure vital signs, stress levels, and hydration levels, as well as monitor diseases and chronic conditions. What’s more, this information is compiled and exchanged with little to no user involvement—in many instances, users are not even aware this information is being tracked. But how can it be used in litigation?
II. Wearable Device Data Used in Civil Litigation
The Fourth Amendment constrains the admissibility of wearable device data in the criminal context. The same is not true in civil litigation, however, where discovery is broader and more extensive.
One of the earliest cases involving wearable device data in civil litigation hails from Canada. There, a plaintiff’s law firm called on Fitbit data to support the plaintiff’s claim that her activity levels declined as a result of a car accident. The plaintiff used this data to show that her activity levels had decreased lower than is typical of someone her age and her profession.[1] One would think this is a quintessential example of why plaintiffs would be eager to turn over their wearable device data during discovery to show that their claims are indeed true. But that has not necessarily been the case.
In Bartis v. Biomet, Inc., for example, the plaintiff brought product liability claims against the manufacturer of an artificial hip implant, claiming to have suffered substantial injuries, including pain and limited mobility.[2] In response to interrogatories, the plaintiff admitted that he consistently wore a Fitbit, which tracked his sleep, heart rate, and steps.[3] The defendants requested the production of the plaintiff’s Fitbit and other wearable device data.[4] Instead of turning over the data, the plaintiff lodged a series of objections running the typical gamut: overly broad, unduly burdensome, not limited in time and scope, not calculated to lead to the discovery of admissible evidence, and potential for unreliability.[5] The court didn’t buy it, finding that the plaintiff’s “activity levels are relevant” and ordering that “a portion of the Fitbit data should be produced, especially given the extremely low burden of production.”[6] The Bartis court also noted inconsistencies across the plaintiff’s claims, which further supported the necessity of production.[7]For example, in his interrogatory answers—and as reflected in his experts’ reports—the plaintiff claimed difficulty walking, but at his deposition, he admitted that he could walk and jog without any pain or discomfort.[8] The court found the Fitbit data relevant to the plaintiff’s alleged injuries.[9] It further rejected the plaintiff’s complaints that the data was unreliable, as that “argument clearly goes to admissibility and weight, not discoverability.”[10]
Bartis came on the heels of another federal case permitting discovery of a personal injury plaintiff’s wearable device data. In Cory v. George Carden International Circus, Inc., the plaintiff alleged that the defendant caused her to suffer a head injury and related injuries and damages.[11] The defendant, in turn, sought the plaintiff’s wearable device data to determine whether the plaintiff performed strenuous activities, as this would be relevant to claims of injury or disability.[12] Although the plaintiff did not challenge the defendant’s request, the court granted the defendant’s motion and ordered the plaintiff to produce “fitness monitoring accessories,” including “Fit Bits and running/walking GPS systems.”[13]
III. Discoverability of Wearable Device Data
As the above cases demonstrate, much of the conversation on wearable technology in the civil litigation context to date has pertained to Fitbit data. That is largely because Fitbit was an early market leader, holding a 67% share of the activity-tracking market in 2014.[14] But, as we all know, wearable technology now extends beyond our trusty Fitbits.
Enter the Apple Watch. In 2021, surveys estimated that over 100 million people actively use an Apple Watch.[15] That number has surely grown. Apple Watches are repositories of information stored within the Cloud and on users’ devices. With nearly every WatchOS update and iteration of the Apple Watch comes new features. The Series 4 model, for example, included an FDA-cleared electrocardiogram, thus rendering it a Class II medical device capable of alerting its user to abnormal heart rhythms. That same model was equipped with an accelerometer and gyroscope hardware, enabling it to detect users’ hard falls by analyzing wrist trajectory and impact. Recently, the FDA cleared a technology that allows Parkinson’s patients to be monitored via their Apple Watches.[16] The University of Michigan School of Public Health and Apple recently launched the “Apple Hearing Study,” which will, in part, utilize the Apple Watch hearing health data to determine how environmental sound exposures impact users’ hearing and stress levels.[17]
This information has obvious relevance in personal injury and other civil litigation. Nevertheless, when it comes to discoverability of this data, “[t]here is surprisingly little precedent.”[18] That is not because there is something unique or protected about the information—it’s just that the technology is relatively new, and litigators are lagging behind in seeking it. It appears that, in the last decade, attorneys have spent more energy writing about the discovery of wearable technology data than actually pursuing it.
Under the familiar discovery standard, a civil litigant may obtain discovery regarding “any nonprivileged matter that is relevant to any party’s claim or defense and proportional to the needs of the case.”[19] Wearable technology data clearly fits the bill—it is relevant by the same reasoning that a plaintiff’s medical records and other health information would be. And it is certainly “reasonably accessible.”[20] It is readily available to users right on their phones.
But how do we get the data from plaintiffs’ phones into defendants’ counsels’ hands?
A. Propound Targeted Written Discovery Requests for the Data.
Wearable device data may be a form of “initial required disclosure” under Federal Rule of Civil Procedure 26(a)(1).[21] The data relates directly to the allegations in a personal injury complaint. As set forth above, this information could support a plaintiff’s or defendant’s claims or defenses by either strengthening or undermining the asserted facts pertaining to injury. The deletion of wearable technology data by a plaintiff could constitute spoliation of evidence.
Rule 34 allows parties to serve discovery requests for the inspection, copying, testing, or sampling of plaintiffs’ electronically stored information, or “ESI.”[22] The only limit being—as mentioned—that the requested ESI is “relevant to any parties’ claim or defense” and “proportional to the needs of the case.”[23]
Defendants’ requests for production should be targeted, accounting for the exact type of data available and the relevant time frame, to avoid being labeled a fishing expedition or invasion of privacy.[24] A blanket request for all data, at all times without regard to the plaintiff is likely to garner an objection and be deemed insufficient.
If a party were, for example, defending against a claim involving a plaintiff’s heart condition, there would be a wealth of relevant information in the Apple Health app. A request for the production of all heart-related data could seek:
All data and electronically stored information regarding your heart condition from any and all Apple Watches, smartphones, tablets, or other electronic devices from one year preceding the date of alleged injury until present, including but not limited to heart rate, heart rate variability, resting heart rate, walking heart rate average, cardio fitness, high heart rate notifications, and electrocardiograms.
Defendants can similarly request evidence of active energy, stand minutes, steps, walking + running distance, stand hours, stair speed, flights climbed, exercise minutes, step length, walking speed, and workouts to address the plaintiff’s claims as to how the alleged heart condition has affected his or her lifestyle. And if one of the plaintiff’s claimed injuries is that sleep is affected, the defendants can request data on the plaintiff’s sleep patterns. All of this information is in the Apple Health app. Defense counsel may similarly request information from wearable devices that may have been submitted to a plaintiff’s employer in conjunction with a health insurance wellness program.
B. Specify the Format for Production.
Rule 34(b)(2)(E)(ii) requires production in the form in which the data is usually maintained if no other form is specified. Because plaintiffs may not be familiar with the production of Apple Watch or wearable technology data, they may object that they cannot produce the information as it is usually maintained or that doing so would improperly require them to “create” new documents that did not previously exist. But this is no different from the production of any other electronic information. We do not produce computer data by shipping our computers—we reproduce that data onto another medium. The same is true for phone data.
Because many plaintiffs’ counsel lack familiarity with wearable technology data, we recommend that defense counsel identify with specificity the medium by which they want the ESI data produced.
One low-burden means of production is simply to request screenshots or printouts of certain data metrics. Anyone with a basic understanding of operating an iPhone is capable of taking screenshots of the information, which would undercut any burdensomeness objection lodged by plaintiffs. But because not everyone is familiar with screenshots or even the existence of the data, defense counsel may create a step-by-step guide for plaintiffs to follow in locating and capturing their relevant information. It should identify with specificity exactly what pages of data the defendant seeks and how to take the screenshot.
Alternatively, third-party data vendors can obtain this information. Vendors can accomplish this collection remotely without requiring plaintiffs to send in their phones, thus weakening any undue burden challenge plaintiffs may make. And the cost of this collection is relatively low, particularly in comparison to how costly electronic discovery can be as a whole (especially to defendants).
C. Backstop Document Requests with Interrogatories and Deposition Questions.
Defense counsel should backstop requests for production with other types of discovery. For instance, defense counsel may ask plaintiffs through interrogatories whether they own and/or use an Apple Watch or similar device.[25] Counsel can also explore the plaintiff’s use of wearable technology in the deposition. If the written discovery response is that no such information exists, that should be confirmed with the plaintiff in his or her deposition.
IV. Admitting Wearable Device Data at Trial
Once at trial, a defendant asking for admission of wearable device information must demonstrate the touchstone requirements of relevance, authenticity, and reliability.
Relevance should be fairly straightforward. Data on activity levels may strengthen or weaken the facts establishing injury. And because some wearables can even measure emotional states or stress levels, there is a potential that data can be admitted for claims of emotional and psychological injury as well.
As for authenticity, parties can establish it through several channels.[26] Federal Rule of Evidence 901(b)(1) allows the device owner to authenticate the data through questioning on the stand. That person appropriately qualifies as a witness with knowledge under the rule. Rule 901(b)(4) can also provide for authenticity through distinctive features of the data—which may, for example, refer to a particular exercise type or location uniquely associated with the plaintiff, thus proving its tie to that individual. Rule 901(b)(9) could potentially allow evidence about the device’s data collection method and accuracy rate to be presented in order to establish authenticity. Finally, Rule 901(b)(3) allows for authentication through a computer forensics expert, who could verify the data’s origin.
Within the authenticity concern lies the issue of reliability. Wearable devices sometimes erroneously track steps, for example, while a user travels by car. The proponent of this evidence must show that its data collection methods are sound by presenting evidence from the manufacturer on error rates or possibly collecting information on subsequent remedial measures taken to correct earlier malfunctions in the devices.
Even if the raw data itself cannot be admitted, the proponent may still get its broad strokes admitted through the testimony of an expert witness, who need not rely on admissible evidence in preparing a report or testifying at trial.[27] A sure-fire way of getting wearable device data before the jury may indeed be to have an expert rely on it as the basis for his or her expert opinion. Depending on the case, an expert witness could also rely on such data to establish that the plaintiff did not suffer from an alleged condition and discredit causation based on the physical metrics shown from the data (i.e., a plaintiff claiming a particular injury would not exhibit the physical data demonstrated from such metrics).
V. Conclusion
As wearable devices continue to grow in popularity, defense counsel should realize their evidentiary value and strategically request production of this type of ESI.
[1] See Parmy Olson, Fitbit Data Now Being Used in the Courtroom, Forbes (Nov. 16, 2014), http://onforb.es/1TSzwJJ.
[2] No. 4:13-CV-00657-JAR, 2021 WL 2092785, at *1 (E.D. Mo. May 24, 2021).
[3] Id.
[4] Id.
[5] Id.
[6] Id. at *2. But see Spoljaric v. Savarese, 121 N.Y.S.3d 531, at *2 (N.Y. Sup. Ct. 2020) (denying a defendant’s request for Fitbit records as they related to plaintiff’s weight loss, finding the request overly broad and speculative).
[7] 2021 WL 2092785, at *2.
[8] Id.
[9] Id.
[10] Id., at *3 (citing Fed. R. Civ. P. 26(b)(1)).
[11] No. 4:13-CV-760, 2016 WL 3460781, at *1 (E.D. Tex. Feb. 5, 2016).
[12] Id. at *1–2.
[13] Id. at *3.
[14] See Peter Rubin, How Fitbit Started the Wearables Craze That Got Us All Moving, WIRED (Sept. 15, 2018), https://www.wired.com/story/how-fitbit-got-us-all-moving/.
[15] See Urian Buenconsejo, Apple Watch Hits 100 Million Active Users | Over 50 Million Americans Have One, Tech Times (Aug. 27, 2021), https://www.techtimes.com/articles/264659/20210827/apple-watch-hits-100-million-active-users-over-50-million-americans-have-one.htm.
[16] See Stephen Nellis, Rune Labs Gets FDA Clearance to Use Apple Watch to Track Parkinson’s Symptoms, Reuters (June 13, 2022), https://www.reuters.com/technology/rune-labs-gets-fda-clearance-use-apple-watch-track-parkinsons-symptoms-2022-06-13/.
[17] See Apple Hearing Study Shares New Insights on Hearing Health, Apple (Mar. 2, 2021), https://www.apple.com/newsroom/2021/03/apple-hearing-study-shares-new-insights-on-hearing-health/.
[18] Bartis, 2021 WL 2092785, at *2.
[19] Fed. R. Civ. P. 26(b)(1).
[20] Fed. R. Civ. P. 26(b)(2)(B) (providing that with respect to electronic discovery in particular, “[a] party need not provide discovery of electronically stored information from sources that the party identifies as not reasonably accessible because of undue burden or cost”).
[21] See Nicole Chauriye, Wearable Devices as Admissible Evidence: Technology Is Killing Our Opportunities to Lie, 24 Cath. U.J.L. & Tech. 495, 520 (2016).
[22] Fed. R. Civ. P. 34(a)(1)(A).
[23] Fed. R. Civ. P. 26(b)(1).
[24] See Bartis, 2021 WL 2092785, at *3 (allowing for the redaction of certain Fitbit data, including information concerning the plaintiff’s heart rate, sleep records, or physical location, as that information was irrelevant and implicated privacy concerns); Spoljaric, 121 N.Y.S.3d 531, at *2 (denying speculative request for authorization to obtain plaintiff’s Fitbit records, as such would be a “fishing expedition”).
[25] See, e.g., Bartis, 2021 WL 2092785, at *1 (determining via interrogatory answers that the plaintiff used a Fitbit).
[26] See John G. Browning, Fitbit Data Brings Another Dimension to Evidence, IADC Committee Newsletter: TECHNOLOGY (July 2015), https://www.iadclaw.org/assets/1/19/Technology_July_2015.pdf.
[27] See United States v. Locascio, 6 F.3d 924, 938 (2d Cir. 1993) (“[T]he facts that form the basis for an expert’s opinions or inferences need not be admissible in evidence ‘[i]f of a type reasonably relied upon by experts in the particular field.’ . . . Thus, expert witnesses can testify to opinions based on hearsay or other inadmissible evidence if experts in the field reasonably rely on such evidence in forming their opinions.” (quoting Fed. R. Evid. 703)).
