NEW YORK — Twitter defied a U.S. government request for records that could identify users behind an account opposed to President Donald Trump, and is challenging the order in court.

The company filed a lawsuit against the federal Department of Homeland Security and its Customs and Border Protection office, charging that their efforts to “unmask” the people behind the account violated the First Amendment.

Twitter says its users have a constitutional right to disseminate such “anonymous and pseudonymous political speech.”

The account in question is @ALT_uscis, a reference to the U.S. Citizenship and Immigration Services office. The account described its users to the Associated Press in February as employees and former employees of the agency.

Twitter declined to comment beyond the lawsuit. DHS likewise declined to comment.

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