The now well established "BYOD," or "bring your own device" trend, creates turbulent waters for an employer to navigate when employees use their personal mobile devices for both business and personal purposes. Along with employee privacy and employer data security concerns, a BYOD policy may subject the data on personal devices to discovery.

An employer's obligation to preserve or produce relevant data contained on an employee's mobile device is a fact-specific analysis that turns on applying the appropriate standard to determine a party's "possession, custody or control" under Federal Rule of Civil Procedure 34. Complicating the analysis is the current circuit split regarding when a producing litigant has Rule 34 "control" over third-party ESI. The Sedona Conference describes the circuit split as falling into the following three broad interpretations of Rule 34 "control:" the legal right standard; the legal right plus notification; and the practical ability standard. See, The Sedona Conference, Commentary on Rule 34 and Rule 35 "Possession, Custody, or Control," 25 Sedona Conf. J. 1, 8 (2024). Under the legal right standard, a producing party has "control" over ESI possessed by a third party where the party has a legal right to obtain the ESI. The legal right standard plus notification imposes the additional obligation to notify the opposing party when, while having no legal right to obtain the ESI, the producing party is aware that a third party has the requested material. Under the practical ability standard, a producing party is deemed to have control over ESI when it has the "practical ability" to obtain the material, even if the party does not have a legal right to do so. Within these broad categories, there remain differences among how district courts apply these standards, and, in a few circuits, district courts have applied both the legal right standard and the practical ability standard.