A recent decision from the New York County Commercial Division reminds litigants that even under New York’s liberal discovery standards, sensitive business information like client lists is not automatically discoverable. In Slice Wireless Services, LLC v. Yakubov, et al. (Index No. 656506/2017, Apr. 22, 2026), Justice Robert R. Reed addressed the outer limits of discovery obligations, emphasizing the protection afforded to proprietary information and the practical boundaries of what a party must produce in discovery. The Dispute Plaintiff Slice Wireless Services, LLC sought expansive post-deposition discovery from Defendants, including additional corporate tax records; and a complete list of Defendant Made by Wifi, Inc.’s clients from 2017 through 2023. Plaintiff argues this information was material and necessary for trial preparation because it went directly to the core issues of liability and damages. Defendants resisted, arguing they had already produced all relevant materials within the applicable timeframe (particularly through 2019, when any restrictive covenants arguably expired). They further contended that the client list constituted protected, proprietary information and that no such comprehensive list even existed in the form Plaintiff demanded. The Court’s Ruling The Court denied Plaintiff’s motion, refusing to compel supplementation of discovery responses or production of Defendant Made by Wifi, Inc.’s client list.  Its reasoning rested on two key principles: (1) discovery is limited to materials within a party’s “possession, custody or control,” and (2) sensitive commercial information such as client lists warrants protection.

1. Discovery Is Not Boundless

The Court reaffirmed that under CPLR 3101, discovery is broad, but not unlimited. A party is only required to produce materials within its “possession, custody, or control,” including what courts have termed “constructive possession”—the documents a party has the practical ability to obtain (Commonwealth of N. Mariana Is. v Can. Imperial Bank of Commerce, 21 NY3d 55, 62-63 [2013]). The Court found that Defendants had met this obligation. With no evidence that their prior responses were incomplete, inaccurate, or misleading, there was no basis to compel supplementation under CPLR 3101(h). The decision underscores a practical reality: discovery obligations are tethered to what actually exists and is accessible to the responding party—not to what might exist in theory.

2. Client Lists May Constitute Protected, Proprietary Information

The Court also refused to compel production of the Defendants’ client list. Citing Leo Silfen, Inc. v Cream, 29 NY2d 387, 392 [1972], the Court recognized that client lists may qualify as trade secrets and constitute protected proprietary information. Importantly, the Court did not rely solely on the sensitive nature of the information. It also highlighted a threshold evidentiary gap: there was no evidence that a comprehensive client list for 2017 through 2023 even existed. Given the nature of Defendants’ business operations, the requested document may have been more conceptual than real. Ultimately, the sensitive nature of the information and the absence of evidence that the client lists existed made the difference. The Court declined to order production “at this juncture,” suggesting caution now, but flexibility down the road. Implications for Commercial Litigants This decision carries practical lessons for parties engaged in discovery disputes in the Commercial Division: First, relevance alone is not enough. Even where requested information goes to the “core” of a claim, courts will weigh the burden, sensitivity, and actual availability of the material. Litigants must show that the discovery is both within the responding party’s “possession, custody or control” (Canadian Imperial Bank of Com., 21 NY3d at 62-63) and is “material and necessary”(CPLR § 3101 [a]). Second, proprietary business information remains protected. Client lists continue to receive heightened scrutiny (Leo Silfen, Inc., 29 NY2d at 392). The Court declined to compel production where the information is sensitive, and its very existence is not established. Third, courts will enforce the “possession, custody and control” boundary. The Court’s decision reinforces that parties are not required to create documents that do not exist or to compile information into new formats simply to satisfy an adversary’s demand. Conclusion Slice Wireless serves as a reminder that New York’s liberal discovery regime has meaningful limits. Courts remain attentive to both the practical realities of document possession and the need to protect sensitive commercial information. The takeaway is clear: discovery operates at the intersection of broad disclosure rules and the practical limits of what exists, is accessible, and warrants protection.  …

Continue Reading Broad But Not Boundless: Policing the Edge of Discovery and Protecting Client Lists in Slice Wireless Services, LLC v. Yakubov, et al.