Pennsylvania is the only state with this law. A Supreme Court ruling just upheld it.

The U.S. Supreme Court on Tuesday narrowly ruled to uphold a Pennsylvania law that requires corporations doing business in the commonwealth to consent to being sued in its courts. The rule is unusual because it allows corporations to be sued by anyone, for conduct anywhere, in Pennsylvania courts. Pennsylvania is the only state with this type of statute.

The decision was made in the case of Mallory v. Norfolk Southern Railway. The plaintiff, Robert Mallory, was a freight-car mechanic for Norfolk Southern for 20 years. After being diagnosed with cancer, Mallory attributed his diagnosis to his time with the company and sued Norfolk Southern.

At the time of his original complaint, Mallory was living in Virginia, where the company is also incorporated, but he filed the suit in Pennsylvania and “pointed to Norfolk Southern’s presence in Pennsylvania, noting that Norfolk Southern manages over 2,000 miles of track, operates 11 rail yards, and runs three locomotive repair shops in Pennsylvania,” the SCOTUS ruling said.

The U.S. Supreme Court’s decision overturned an earlier judgment from the Pennsylvania Supreme Court that sided with Norfolk Southern, which had challenged Mallory’s suit and claimed it violated the due-process clause of the Fourteenth Amendment.

Pennsylvania law requires that businesses incorporated in the state or out-of-state firms that conduct “a continuous and systematic part of its general business within this commonwealth” must agree to answer to suits filed in the state. In doing so, businesses gain status as a registered foreign corporation within Pennsylvania.

Pennsylvania is the only state with such a law, though the ruling could prompt more states to enact similar rules, giving consumers and workers “more choices of where to sue and subjecting corporations to suits in courts they may view as hostile to business,” the New York Times reported.

One attorney said the decision opened states up to “litigation tourism.”

“Not only does it give free reign to all litigation tourism in Pennsylvania, but it opens the door to any other state potentially to do the same thing,” James M. Beck, attorney at ReedSmith, wrote on the Lexology blog.

“Before today’s ruling, it was understood that general personal jurisdiction over a corporation could be found in only two very distinct places: the state of the company’s headquarters and the state of the company’s incorporation,” Saxon Guerriere, an attorney with Gordon Rees Scully Mansukhani, told the Society for Human Resource Management. “However, the holding of Mallory now allows a corporation to be hauled into court in any state in which it has consented to jurisdiction.”

The ruling could increase “forum shopping by plaintiffs and uncertainty for defendants,” warned attorneys from Locke Lord LLP. “For now, corporations that do business in multiple states will need to closely monitor developments and take state-specific approaches to challenging jurisdiction where appropriate.”

In considering the claim that the law violates the due-process clause of the Fourteenth Amendment, the Supreme Court voted in a 5-4 split against Norfolk Southern.

The majority of justices rejected Norfolk Southern’s argument that the company was entitled “to a more favorable rule, one shielding it from suits even its employees must answer” under the Fourteenth Amendment.

Justice Neil Gorsuch wrote for the majority, which included Justices Clarence Thomas, Sonia Sotomayor, and Ketanji Brown Jackson. Justice Samuel Alito voted with the majority, but he wrote his own opinion.

At the heart of the majority’s decision was a precedent set in a similar case decided by the court in 1917. In Pennsylvania Fire Insurance Co. of Philadelphia v. Gold Issue Mining & Milling Co., the justices at the time voted unanimously to uphold a similar law enacted when the insurance company obtained permits to do business in Missouri. Though neither Pennsylvania Fire Insurance nor Gold Issue Mining & Milling were based in or operated out of Missouri, the insurance company “had agreed to accept service of process in Missouri on any suit as a condition of doing business there,” Gorsuch wrote.

In dissent were Justices Amy Coney Barrett, Elena Kagan, Brett Kavanaugh, and Chief Justice John Roberts.

Barrett wrote in the 18-page dissent that Pennsylvania’s law unfairly harmed other states’ rights because it imposed “a blanket claim of authority over controversies with no connection to the commonwealth.”

She added: “Pennsylvania’s power grab infringes on more than just the rights of defendants — it upsets the proper role of the states in our federal system.”

In his separate opinion, Alito suggested that the lower court could rule in Norfolk Southern’s favor when they rehear the case.

“In my view, there is a good prospect that Pennsylvania’s assertion of jurisdiction here — over an out-of-state company in a suit brought by an out-of-state plaintiff on claims wholly unrelated to Pennsylvania — violates the commerce clause,” he said.

The commerce clause was not considered by the U.S. Supreme Court in this case, and only the due-process clause was argued.

Alito wrote, “at the very least, the [Pennsylvania] law imposes a ‘significant burden’ on interstate commerce.” He added: “I am hard-pressed to identify any legitimate local interest that is advanced by requiring an out-of-state company to defend a suit brought by an out-of-state plaintiff on claims wholly unconnected to the forum state.”