E-Seller Litigation Remained Lower in Q4 Following Rule Changes in Key Districts

RPX’s latest quarterly report shows that litigation from operating company plaintiffs increased by 26% in Q4 2025 compared to the fourth quarter last year. Operating company filings last quarter were also 26% higher than in Q3 2025 and were 10% greater than the trailing Q4 average. Additionally, operating company litigation last year was up by nearly 11% from 2024—which in turn was also up from 2023, albeit by a more modest 9%.

However, these data leave out another distinct category of litigation filed by a small group of design and utility patent owners targeting copycats and counterfeiters selling products online. RPX excludes such “e-seller” cases from analyses of district court litigation because they tend to follow a different dynamic compared to what one might consider the usual patent suit. These e-seller cases sometimes name hundreds of defendant entities, many of which may be merely online storefronts or aliases for the same ultimate parent. Also, plaintiffs primarily seek injunctive relief instead of damages, and their cases often end with the e-seller defendant’s failure to answer, followed by a default judgment.

This category of litigation is shown in grey below to illustrate its magnitude. As shown by the rightmost bar, e-seller litigation in Q4 2025 accounted for 928 defendants added, or 52% of all litigation during the quarter. As was also the case in Q3, this represents a much lower volume of e-seller litigation than in recent quarters past. While the lower counts for Q3 and Q4 are still subject to the caveat about defendants potentially having multiple online storefronts, as noted above, the decrease could also be related to efforts by some judges to apply stricter procedural rules to e-seller cases, as detailed in RPX’s Q3 in Review: In the Northern District of Illinois, by far the top venue for such litigation, District Judge John F. Kness issued an August 2025 order that criticized the “deluge” of such litigation, finding that these cases stretch the bounds of procedural rules “past their breaking point”. Because these cases routinely award preliminary injunctive relief without adversarial proceedings, involve widespread sealing, and rely upon improper mass joinder of defendants, Judge Kness held that the plaintiffs here should instead obtain the relief sought “by other means”.

The District of New Jersey appears to be following suit: On September 25, Chief Judge Renée Marie Bumb issued an order requiring e-seller plaintiffs to specifically and plausibly allege personal jurisdiction, including the contacts of each named defendant with the forum—stating that “[t]he law is well-settled that simply being an online seller on Amazon isn’t enough”. The order also limits each e-seller complaint to a “single defendant or group of defendants acting under the same operator”.

See RPX’s fourth-quarter review for more on some of the top patent litigation trends last year.