The US supreme court temporarily blocked a Texas law that would bar social media companies from removing user posts based on their "viewpoint", as lower courts battle over whether it would violate first amendment rights.
In a 5-4 decision, the justices granted a request from two technology industry groups that have argued the Republican-backed measure would turn platforms into "havens of the vilest expression imaginable".
Tuesday's ruling reverses a decision made on 11 May by a court of appeals, which industry groups including companies such as Facebook, Twitter and YouTube sued to block. They argue the law would be in violation of the right to editorial discretion on their platforms under the first amendment to the US constitution.
A wide range of civil rights organizations, including the NAACP, the Chamber of Progress, and ADL, had also urged the supreme court to block the law from going into effect. In a statement, the Chamber of Progress CEO, Adam Kovacevich, said the law would "force social media to host racist, hateful, and extremist posts".
"Anti-content moderation laws are so actively harmful that our nation's highest court took an emergency appeal to prevent this law from taking effect," he said.
The conservative justices Samuel Alito, Clarence Thomas and Neil Gorsuch issued a written dissent while the liberal justice Elena Kagan said she would have denied the industry groups' request.
In Alito's dissenting opinion, he said he "is not comfortable intervening at this point in the proceedings" because he had "not formed a definitive view on the novel legal questions that arise" from it.
The Texas law was passed by the state's Republican-led legislature and signed by its Republican governor. Its passage comes as US conservatives and rightwing commentators complain that big tech companies are suppressing their views.
They cite as a prominent example Twitter's permanent suspension of Donald Trump shortly after the 6 January 2021 attack on the US Capitol by a mob of his supporters, with the company citing "the risk of further incitement of violence".
The law, formally known as HB20, forbids social media companies with at least 50 million monthly active users acting to "censor" users based on "viewpoint" and allows either users or the Texas attorney general to sue to enforce it.
In signing the bill last September, the Texas governor, Greg Abbott, said: "There is a dangerous movement by some social media companies to silence conservative ideas and values. This is wrong and we will not allow it in Texas."
The industry groups said the state law would unconstitutionally allow for government control of private speech. Restricting editorial control, the groups said, "would compel platforms to disseminate all sorts of objectionable viewpoints - such as Russia's propaganda claiming that its invasion of Ukraine is justified".
"Instead of platforms engaging in editorial discretion, platforms will become havens of the vilest expression imaginable: pro-Nazi speech, hostile foreign government propaganda, pro-terrorist-organization speech, and countless more examples."
Similar laws have been introduced elsewhere in the US, including in Florida, where, unlike in Texas, an unanimous ruling by the court of appeals for the eleventh circuit blocked the legislation from going into effect.
"The conflicting circuit court decisions heightened the need for the supreme court to weigh in," said Kovacevich. The bill may still make its way back to the supreme court for a definitive ruling as the legal battle over it continues to play out in lower courts.