Following in Google's wake, Twitter has released for the first time data on government requests for user information. The table shows that the US government is significantly more interventionist in terms of the number of times it has asked Twitter to hand over information than any other government in the world.
From 1 January 2012, the US made 679 user information requests out of a total of 849, compared with 98 requests from the Japanese government, 11 each from the Canadian and British governments and under 10 for a slew of other countries." Read more
See also
Williams, Matt. "Twitter Forced to Release Occupy Protester's Tweets to New York Court." The Guardian, July 2, 2012.