NEW YORK — A criminal-court judge in Manhattan has ruled that Twitter must turn over to prosecutors messages sent by a Brooklyn writer during the Occupy Wall Street protests last fall. In doing so, the judge, Matthew Sciarrino Jr., indicated that although private speech was protected, the same did not apply to public comments on Twitter.

"The Constitution gives you the right to post, but as numerous people have learned, there are still consequences for your public posts," Sciarrino wrote on Monday. "What you give to the public belongs to the public. What you keep to yourself belongs only to you."

The writer, Malcolm Harris, was one of about 700 protesters arrested in October while walking on the roadway of the Brooklyn Bridge. He was charged with disorderly conduct, a violation.

In January, the Manhattan District Attorney's Office subpoenaed all messages that he had posted to Twitter from two days before the Occupy Wall Street protests began in September through the end of 2011.

Harris' messages, which are no longer publicly available, are of interest to prosecutors because they may contradict an argument they expect him to make at trial: that the police led or escorted protesters off the pedestrian paths and into the bridge's roadway.

His lawyer, Martin Stolar, filed a motion to quash the subpoena, saying it had not been delivered properly, was overly broad and was issued for an improper purpose.

Sciarrino dismissed the motion in April, writing that Harris lacked the standing to oppose the subpoena because under Twitter's policies, he had granted the company the "worldwide, nonexclusive, royalty-free" right to distribute his messages, which were all publicly available.

Twitter itself then sought to quash the subpoena.

But in the decision released Monday, Sciarrino ordered it to turn over Harris' messages.

While noting that laws regarding social media were evolving, he held that public speech, regardless of the forum, did not enjoy the same protections as private speech.