Twitter is suing the US government after it demanded it reveals the identity of an anti-Trump account.
The @ALT_USCIS profile was an anonymous profile account criticising President Trump’s immigration policy.
The account claimed it was being run by federal employees at the United States Citizenship and Immigration Services.
Twitter has requested a court block the Trump administration’s request, calling it a matter of free speech.
The challenge was filed in San Francisco, where the micro-blogging service is based.
“The rights of free speech afforded Twitter’s users and Twitter itself under the First Amendment of the US Constitution include a right to disseminate such anonymous or pseudonymous political speech,” the company argued.
It added that the government “may not compel Twitter to disclose information regarding the real identities of these users without first demonstrating that some criminal or civil offense has been committed”.
The move was backed by the American Civil Liberties Union.
“We are pleased to see Twitter standing up for its users’ rights, and the ACLU will soon be filing documents in court on behalf of this user,” the ACLU said in an emailed statement.
“To unmask an anonymous speaker online, the government must have a strong justification. But in this case the government has given no reason at all, leading to concerns that it is simply trying to stifle dissent.”