Seven people from the Knight First Amendment Institute at Columbia University in New York, all of whom have been blocked by Trump after criticizing the president, filed a lawsuit at the Manhattan federal court on Tuesday.

The lawsuit asks a judge to stop Trump and his media team blocking critics following his personal account - @realdonaldtrump - which has 33 million followers, 14 million more than the official US presidential account @POTUS and 19 million more than @WhiteHouse.

They claim that Trump is imposing an unconstitutional restriction on their ability to participate in a public forum. They also claim that access is being curtailed to statements that the government has already made available to the public and that the block hinders petitioning the government for "redress of grievances."

The case raises questions about how to interpret and apply the US constitution in the social media era. 

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"The @realDonaldTrump account is a kind of digital town hall in which the president and his aides use the tweet function to communicate news and information to the public, and members of the public use the reply function to respond to the president and his aides and exchange views with one another,” the lawsuit said.

The lawsuit also named as defendants White House Press Secretary Sean Spicer and Dan Scavino, White House director of social media.

A new legal frontier

Jameel Jaffer, director of the Knight First Amendment Institute, said dozens of people had made statements of support after his organization told the White House three weeks ago it wasn't permitted to block individuals from following the president's @realdonaldtrump account.

"It's fair to say that this is a new frontier," Jaffer said. "The First Amendment principle is well-settled, but the applicability of that principle to this context isn't an issue that the courts have yet had many occasions to address."

Neil Richards, a professor at Washington University's Law school, specializing in First Amendment theory, told Wired news website that determining whether the president's Twitter feed represents a public forum is complicated.

"The law here is famously muddled, because it's trying to prevent the government from discriminating against people who speak on public streets and parks, but it's trying to fight the urge to make everything a public forum," he said.

Some blocked tweeters

Philip Cohen, a University of Maryland sociology professor, was blocked after he called Trump a "corrupt incompetent authoritarian."

Holly Figueroa, a national political organizer and songwriter, was cut off on May 28 after posting an image of the pope looking incredulously at Trump, along with the statement: "This is pretty much how the whole world sees you," the lawsuit said.

Tweets as official statements

Federal agencies and courts treat Trump's tweets as official statements and the National Archives and Records Administration has advised the White House that the tweets must be preserved under the Presidential Records Act, the lawsuit said.

A federal judge in Washington DC ruled recently that a local official's Facebook account was a public forum under the First Amendment, but higher courts have not yet addressed the issue, Jaffer said.

Skeptics argue that Trump's account is personal, not official, and that he has the right to block people he considers trolls or antagonists.

Dawn Dearden, a spokeswoman for government lawyers, declined to comment.

jbh/gsw (AP, Reuters)