Microsoft on Thursday disclosed for the first time the number of requests it had received from government law enforcement agencies for data on its hundreds of millions of customers around the world, joining the ranks of Google, Twitter and other Web businesses that publish so-called transparency reports.
The report, which Microsoft said it planned to update every six months, showed that law enforcement agencies in five countries Britain, France, Germany, Turkey and the United States accounted for 69 percent of the 70,665 requests the company received last year.
In 80 percent of requests, Microsoft provided elements of what is called noncontent data, like an account holder's name, sex, email address, IP address, country of residence, and dates and times of data traffic.
In 2.1 percent of requests, the company disclosed the actual content of a communication, like the subject heading of an email, the contents of an email or a picture stored on SkyDrive, its cloud computing service.
Microsoft said it disclosed the content of communications in 1,544 cases to law enforcement agencies in the United States and in 14 cases to agents in Brazil, Canada, Ireland and New Zealand.
"Government requests for online data are like the dark matter of the Internet," said Eva Galperin, a global policy analyst at the Electronic Frontier Foundation in San Francisco, which has campaigned for greater disclosure.
The law enforcement requests concerned users of Microsoft services including Hotmail, Outlook.com, SkyDrive, Skype and Xbox Live, where people are typically asked to enter their personal details to obtain service.
Google was the first major Web business, in 2010, to report the number of legal requests it had received for information. Since then, Twitter, LinkedIn and some smaller companies have also begun reporting, but businesses like Apple and Yahoo have not.
Microsoft provided two types of detail in its report that rivals have not addressed in similar fashion.
It described the reasons it had rejected some requests, and it listed separately by country how it had responded to requests for the content of communications and for noncontent data.
It also published separate information for the Internet communication service Skype, which is based in Luxembourg and is subject to national and European Union laws.