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What Centuries of Common Law Can Teach Us About Regulating Social Media


Morgan Ricks (@MorganRicks1) is the Herman O. Loewenstein Chair in Law at Vanderbilt Law School.

Ganesh Sitaraman (@GaneshSitaraman) is the New York Alumni Chancellor's Chair in Law at Vanderbilt Law School.

This morning, the Supreme Court will hear arguments in the most anticipated cases of the year for the future of regulating tech platforms, NetChoice, LLC v. Paxton and Moody v. NetChoice, LLC. At the core of these two cases is whether Florida and Texas can regulate social media platforms, including by setting rules for content moderation and exclusion of users. 

Much of the debate about the case focuses on the First Amendment and whether the platforms are best analogized to publishers. But there is another important argument that the Supreme Court will likely confront: whether platforms are akin to “common carriers.” 

As we describe in a new paper, common carriage is an old concept, dating back to medieval English law and with a long pedigree in the American legal tradition. The core idea is that businesses that provide essential services to commerce and that tend toward monopoly or oligopoly need to be governed by special rules. Prior to the industrial era, wharfs, ferries, grain warehouses, markets, and inns were included in this category. Such businesses were said to be “clothed with the public interest.”

Among the rules that common carriers had to follow was an equal access mandate: They had to “serve all comers” impartially, without special privileges or discrimination. Carriers could, however, exclude people for good reason. Acceptable justifications for exclusion included illegal behavior, harm to users, or a danger to the service itself.

As new technologies emerged, judges determined whether these common carriage rules applied, reasoning by analogy to existing industries. In one instance, a court in Kentucky designated a telephone provider a common carrier merely five years after Alexander Graham Bell invented the communications technology. “The law must adapt itself to the new subjects that are brought within the range of judicial action,” the court said. “And Courts must reason by analogy from things that are settled, in order to establish principles to govern things that are unsettled.” 

Over time, state legislatures and Congress stepped in, passing statutes regulating common carriers. One after another in the late 19th and early 20th century, new technologies were regulated in order to ensure that they served the public interest: the telegraph, the telephone, railroads, oil and gas pipelines, electricity, trucking, maritime shipping, airlines.

Today, tech platforms, including social media, are the new common carriers. Not only do they tend toward monopoly or oligopoly, but they have become increasingly essential to modern life–something that tech executives welcome. Mark Zuckerberg once framed his ambition as creating a “public utility” and Elon Musk has said he wants to turn X (Twitter) into an “everything app.” At the same time, business publications and consultants have been advising companies for years on how to develop social media strategies—precisely because it is critical to their success. 

Some have argued that tech platforms cannot be common carriers. The Eleventh Circuit, for example, found that social media platforms were not common carriers and that Florida legislation imposing common-carrier-type regulation on social media companies ran afoul of the First Amendment. Importantly, the court said that “social-media platforms have never acted like common carriers,” observing that they do not publicly hold themselves out as accepting anyone as a user: they have terms of service that condition use. But common carriers of the past also had terms of service; such conditions are no barrier to a common carrier designation.  

Others have argued that social media platforms are not common carriers because they do not “carry” anything. Google made this argument in its defense against a common law suit from the Attorney General of Ohio. But neither did wharves, inns, or financial exchanges. 

(The Fifth Circuit, in assessing Texas’s law regulating social media platforms, did not make either of these mistakes. But it was not quite accurate either in its understanding of common carriage: it offered an incomplete discussion of the common carrier’s right to exclude, covering only a limited number of the exceptions to the duty to serve.)

What are the consequences of classifying social media companies as common carriers? Some are excited about the prospect because they believe it would prevent deplatforming – the exclusion of individuals or content from these services. Others fear this prospect because they worry about unmoderated user content featuring hate speech, threats of violence, and child-abuse material, among other activities that are illegal or simply unacceptable to society.

While the underlying concerns are real in both directions, the designation as a common carrier shouldn’t be caught up in debates about deplatforming. The reason, as one of us has shown in a new paper, is that common carriers always had the ability to exclude some users as long as it was reasonable. In fact, these exceptions have always been necessary to ensure the service’s continuity, prevent illegal behavior, and protect users as well as the general public.

Of course, common carriage principles, including reasonable deplatforming, will apply differently in different contexts. The railroads of the 19th century operated in a business-to-business context that is distinct from the telephone, and both of those are different from the realm of social media. And the First Amendment has its own interests and contours, which implicate a variety of civic, democratic, and free-speech values. The Supreme Court will have to confront these varied dynamics in NetChoice, LLC v. Paxton and Moody v. NetChoice, LLC.

Understanding that tech platforms are common carriers under the common law nevertheless helps clarify where the Court should focus: on the First Amendment. What the Supreme Court will decide is anyone’s guess, but it shouldn’t base its decision on a faulty understanding of the history and tradition of common carriage that has long defined the American approach to platform regulation.