Author ORCID Identifier

Matthew Sag 0000-0003-2381-1028

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Supreme Court, Injunction, Federal district courts, Patent infringement, Copyright infringement, eBay, Delay in adoption, Citation trends


This Article reports on new empirical evidence discrediting the widely held view that judges have resisted applying the Supreme Court’s teachings in eBay Inc. v. MercExchange, L.L.C. about injunctive relief in copyright cases. That 2006 patent law decision ruled that courts should not automatically issue injunctions upon a finding of infringement; instead, plaintiffs must prove their entitlement to injunctive relief. eBay had a seismic impact on patent litigation and greatly reduced the threat that small infringements could be leveraged into billion-dollar settlements. Yet prior empirical work, at least one major copyright law treatise, and many articles assert that eBay had little or no effect on the neighboring arena of copyright law. They assert that eBay was rarely cited and infrequently applied.

By examining a longer timeline of cases and more carefully distinguishing between default judgments and contested cases, we find substantial evidence that eBay has become profoundly important in copyright injunction cases. The decision’s true impact as well as the language judges have been using to discuss the need to balance hardships to plaintiffs and defendants when considering whether to grant copyright injunctions. We also find evidence suggesting that injunctions have become more difficult to obtain in the aftermath of eBay. Our data suggest that the early impression that eBay had little impact in copyright cases was a product of hysteresis—a time lag between cause and effect—as lower courts initially resisted, but eventually embraced, eBay.

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Publication Title

William & Mary Law Review


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