San Francisco - Twitter said in its first "transparency report" that the number of government requests for user information or to block content is rising in 2012.
"We've received more government requests in the first half of 2012, as outlined in this initial dataset, than in the entirety of 2011," Twitter's legal policy manager Jeremy Kessel said in a blog post.
The overwhelming number of requests came from the US, accounting for 679 of the 849 requests for user information. In 75% of the US cases, Twitter gave some or all information.
The largest number of Twitter users are located in the US.
After the US was Japan with 98 cases and Britain and Canada with 11 each.
"One of our goals is to grow Twitter in a way that makes us proud," Kessel said.
"This ideal informs many of our policies and guides us in making difficult decisions. One example is our longstanding policy to proactively notify users of requests for their account information unless we're prohibited by law."
Twitter said it received 3 378 "takedown" notices so far this year for copyright violations and removed 38% of the requested tweets.
There were also six cases in which courts or governments requested removal of tweets. None were in the US, and none was removed, Twitter said.
The transparency report is modelled after a similar effort from Google.
In addition to the transparency report, Twitter said it was partnering with a company called Herdict, which "collects and disseminates real-time, crowd-sourced information about internet filtering, denial of service attacks, and other blockages".
"This new partnership aims to drive more traffic and exposure to Herdict, while also empowering the web community at large to help keep an eye on whether users can access Twitter around the world," Kessel said.
The two initiatives, he said "are an important part of keeping the Tweets flowing".
The news came the same day a New York judge ordered Twitter to turn over data on one of its users involved in the Occupy Wall Street protest movement, in a case watched closely as a test of online freedom of speech.
The judge said that the tweets are not private information and thus not subject to the constitutional guarantee of privacy.
Twitter said it was studying its next move.
"We are disappointed in the judge's decision and are considering our options," a statement from the San Francisco firm said.
"Twitter's terms of service have long made it absolutely clear that its users 'own' their content. We continue to have a steadfast commitment to our users and their rights."