Last week, Donald Trump Jr. complained of being blocked from Instagram, continuing a long list of political censorship complaints against Google, Facebook, Twitter and Instagram, chiefly by conservative commentators.

The tech companies are private companies, and therefore not automatically covered by the First Amendment free speech protections which apply to the government. However, past Supreme Court cases show that the First Amendment can be applied to private organizations if those organizations have effectively replaced the “public square” as the central location for political debate. The big tech Internet sites are rapidly heading in this direction, and may ultimately be covered by the First Amendment as well.

The Supreme Court applied the First Amendment to a private company in Marsh vs. Alabama (1946). In that case, a Jehovah’s Witness sought to distribute religious literature on the streets of a company town – one of the giant industrial sites that included both a factory and a surrounding town, all owned by the employer. The Court ruled that the company town had become the equivalent of the public streets and parks where free speech is protected. Justice Hugo Black wrote, “Ownership does not always mean absolute dominion. The more an owner, for his advantage, opens up his property for use by the public in general, the more do his rights become circumscribed by the statutory and constitutional rights of those who use it….To act as good citizens, they <the citizens> must be informed. In order to enable them to be properly informed, their information must be uncensored…When we balance the Constitutional rights of owners of property against those of people to enjoy freedom of press and religion, as we must here, we remain mindful of the fact that the latter occupy a preferred position.”

The same precedent was applied to protect public speech in shopping malls. This began with a case called Amalgamated Food Employees Union Local 590 v. Logan Valley, where the Court found peaceful picketing at the privately owned Logan Valley Mall fell under the First Amendment protections of Marsh.

Over time, the shopping center free speech cases were effectively reversed, except where there is a specific state constitutional speech protection. The Court ultimately determined that shopping malls were meant for commerce, not for speech, and that the free speech rights became unduly disruptive to the fundamental use by retailers and shoppers.

When the application of the First Amendment to tech companies has been tested so far, the tech companies have also been spared the free speech obligations. For example, in Cyber Promotions v. America Online, (1996) a district court ruled AOL could block mass email advertisements, leading the way to spam filters.

However, the Marsh case itself has never been reversed and floats like an iceberg, ready to sink big tech censorship of political speech if the companies become too dominant a location for public policy debate and too abusive of their power. Some broad state constitutional free speech protections also still exist. And the day may be coming when the facts of big tech censorship of political speech lead a Court to apply the Marsh precedent to these companies as well.

The Court has already recognized the extraordinary role that the Internet has begun to play as the most important location for political speech and debate in our modern world. In 2017, in the Packingham vs. North Carolina case, a unanimous Supreme Court cited the First Amendment to stop a North Carolina law that made it a felony for registered sex offenders to use social media websites like Facebook and Twitter.

Justice Kennedy wrote, “A fundamental principle of the First Amendment is that all persons have access to places where they can speak and listen, and then after reflection, speak and listen once more….A basic rule, for example, is that a street or a park is a quintessential forum for the exercise of First Amendment rights…While in the past, there may have been difficulty in identifying the most important places (in a spatial sense) for the exchange of views, today the answer is clear. It is cyberspace – the vast democratic forums of the Internet in general, and social media in particular. Seven in ten American adults use at least one Internet social networking service…Facebook has 1.79 billion active users. This is about three times the population of North America…On Facebook, for example, users can debate religion and politics with their friends…And on Twitter, users can petition their elected representatives and otherwise engage them in a direct manner. Indeed, Governors in all 50 states and almost every member of Congress have set up accounts for this purpose.”

As the Internet continues to grow, the reason to apply First Amendment to protect free political speech on social media becomes ever more compelling. Clearly, there is much more reason to apply free speech protections to a site designed specifically for speech and information – such as Google, Twitter, and Facebook – than to a shopping mall that was never primarily intended for this purpose. Other dominant locations for political speech in America, such as the broadcast networks in their heyday, were subject to free speech protections through the Fairness Doctrine or other means because they depended on government licenses to operate. Telephone networks simply carried all speech, as a common carrier utility. America has never before had the private owners of the dominant forum for political speech use their private ownership to censor political opinions, or to limit the nation’s ability for political debate.

Ultimately, if a handful of giant tech sites gain a de facto monopoly over political speech and then abuse their power, the censored political speakers will be able to bring suit, and the Court can and will apply the First Amendment to protect speech. The precedents are in place. For their own good and for the good of society, those tech giants should already consider themselves as the modern public square, and should already treat all political speakers fairly and equally as if the First Amendment was in place today.

K.S. Bruce writes the “In This Corner” column of opinion and analysis for RealClearLife.