At the outset of many class actions, the plaintiff must first clear the personal jurisdiction threshold. Stated more directly, the plaintiff needs to establish that the defendant has "minimum contacts" with the forum in which the court sits, so that the court has the power to make decisions with respect to that defendant. There are two principal means by which to establish personal jurisdiction. First, through the easier of the two, general jurisdiction, a defendant's contacts with the jurisdiction are so systematic and continuous that they are effectively "at home" in the jurisdiction. Goodyear Dunlop Tires Operations, S.A., v. Brown, 564 U.S. 915, 919 (2011). But often plaintiffs don't wish to play on the defendant's home turf; rather, plaintiffs want to be the home team. Insofar as the defendant is not "at home" in that jurisdiction, plaintiffs often turn to the second means—specific jurisdiction, or claims-based personal jurisdiction—where personal jurisdiction hinges on "an affiliation between the forum and the underlying controversy." Id. (cleaned up). 

The Supreme Court applied the specific jurisdiction rule to a mass action involving an alleged defect in Plavix, a blood-thinner sold by Bristol-Myers. In Bristol-Myers Squibb Co. v. Superior Court of California, San Francisco County, 582 U.S. 255, 259–60 (2017), a group of plaintiffs—most of whom were not California residents—sued Bristol-Myers in California Superior Court. Although none of the non-resident plaintiffs were prescribed Plavix from California physicians or were injured or treated in California, they argued that California was linked to their injuries through a distribution agreement between Bristol-Myers and the drug wholesaler McKesson. Id. at 259–60. The Supreme Court held the link insufficient because "it is not alleged that BMS engaged in relevant acts together with McKesson in California." Id. at 268. Given the lack of any perceived nexus between Bristol-Myers' Plavix-related activities in California and the nonresidents' alleged injuries, the majority concluded that California state court lacked personal jurisdiction over the non-resident plaintiffs' claims.