The company surrendered the micro-blogging posts - an inch-high stack of paper inside a mailing envelope - to Manhattan Criminal Court Judge Matthew Sciarrino. They will remain under seal while a request for a stay by the protester, Malcolm Harris, is heard next week in a higher court.

Harris, 23, was one of hundreds arrested during a mass protest on the Brooklyn Bridge in October 2011. The Manhattan district attorney's office wants the tweets, which are no longer available online, to try to undermine Harris' argument that police appeared to lead protesters onto the bridge's roadway only to arrest them for obstructing traffic.

Twitter and Harris had challenged the subpoena but Sciarrino rejected their arguments in June. Twitter has filed an appeal, which is scheduled to be heard in November.

The case involves a thorny legal question that has rarely, if ever, been tackled by courts: whether Twitter users have the right to go to court to fight requests from law enforcement for their tweets.

Twitter and Harris argued that Harris, as the author of the tweets in question, should have legal standing to combat the subpoena. Twitter's terms of service make clear that users have a proprietary interest in their records, according to the company's appeal.

Sciarrino, however, has said only Twitter can legally challenge a law enforcement request for tweets, since it is the company, not the user, that owns the content in question. He compared it to a subpoena of bank records, which courts have found cannot be challenged by the account holder.

CONCERN FROM PRIVACY ADVOCATES

The case has drawn interest from privacy advocates, including the Electronic Frontier Foundation (EFF) and the American Civil Liberties Union (ACLU), which have filed an amicus brief in support of Twitter's appeal.

They are concerned the ruling could set a precedent putting the onus on social media companies to try to protect their users from criminal prosecution.

"It's what I would call a canary-in-a-coal-mine case," said Marcia Hofmann, a lawyer with the EFF. "I am concerned that companies will look at this case and say it's not a good idea to push back against governments we think are overreaching. That's troubling."

Twitter had faced a Friday deadline to comply with the subpoena or face contempt and a heavy fine.

Aden Fine, an attorney with the ACLU, said Friday's outcome demonstrates the importance of ensuring that users, not companies, have the right to oppose subpoenas for their content.

"Twitter should be applauded for standing up for its users, but the unfortunate reality is that only the individual users have sufficient incentives to defend their constitutional rights," he said in an email.

While Sciarrino refused Twitter's request to wait until after its appeal is heard, he urged the appeals court not to deem the matter moot just because the tweets have been handed over.

"I strongly encourage the appellate court ... to decide the case on the merits, as I too agree that this is a more important issue than maybe the trial itself," Sciarrino said.

Harris' lawyer, Martin Stolar, said he was disappointed that Twitter had handed over the messages but vowed to continue to challenge the subpoena.

"We're not giving up the fight here," he said following the court session, as Harris stood by his side.

The district attorney's office declined to comment on Friday's court hearing.

The surrender of Harris' tweets comes as the Occupy movement prepares to mark its one-year anniversary next week.

Activists in the movement, which last fall sparked a national conversation about economic inequality and coined the catch phrase "We are the 99 percent," aim to surround the New York Stock Exchange and stage a sit-in on Monday.

(Reporting by Joseph Ax; editing by Bill Trott and Todd Eastham)