(SAN FRANCISCO) — Twitter Inc on Friday dropped a lawsuit it filed the previous day against the U.S. government, saying the government had withdrawn a summons for records about who was behind an account critical of President Donald Trump.

A lawyer for the social media company, Mark Flanagan, wrote in court papers that a U.S. Justice Department lawyer told Twitter about the withdrawal of the summons on Friday and that the demand “no longer has any force or effect.”

It was not immediately clear why the government had withdrawn the summons or whether it had closed an investigation it said it was conducting. The Justice Department, which defends federal agencies in court, declined to comment. The Department of Homeland Security, which issued the summons, had no immediate comment.

Twitter cited freedom of speech as a basis for not turning over records about the account, @ALT_uscis. The people behind the account have not disclosed their identities, but the use of “ALT” with a government agency acronym has led many to assume government employees are behind such tweets.

The lawsuit said the account “claims to be” the work of at least one federal immigration employee.

The acronym U.S. CIS refers to U.S. Citizenship and Immigration Services, and the account describes itself as “immigration resistance.” Trump has vowed to build a wall along the U.S. border with Mexico and has promised to deport millions of illegal immigrants.

Following Trump’s inauguration in January, anonymous Twitter feeds that borrowed the names and logos of more than a dozen U.S. government agencies appeared to challenge the president’s views on climate change and other issues. They called themselves “alt” accounts.

A Twitter spokesman declined to comment beyond the court papers.

The lawsuit gave Twitter a chance to assume a favorite role as a defender of free speech, offering a respite for a company that has struggled recently to expand its audience, excite investors or attract new revenue streams.

On Thursday, Senator Ron Wyden, an Oregon Democrat, said in a statement that the summons was a waste of resources to try to uncover an anonymous critic, and he called on the Homeland Security inspector general to investigate who directed the “witch hunt.”

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