Facebook Inc said in a report on Wednesday that government demands for its user data surged in the first half of 2015, taking a trend that began at least two years ago when the company started revealing such requests to new heights.

Government access to personal data from telephone and Web companies has become a contentious privacy issue since former spy agency contractor Edward Snowden revealed surreptitious surveillance programs.

The technology industry has pushed for greater transparency on government data requests, seeking to shake off concerns that they are working with the government and violating user privacy.

Facebook's biannual report is one of the chief indicators of government interest in the company's data. The social media giant is generally not allowed to publicize specific requests by law enforcement and spy agencies.

Government requests for account data globally jumped 18 per cent in the first half of 2015 to 41,214 accounts, up from 35,051 requests in the second half of 2014, Facebook said in the report posted on its website.

Canada: 410 requests Jan.-June 2015

In the first half of this year, Facebook took down 20,568 posts and other pieces of content that violated local laws, more than doubling the number taken down in the second half of 2014. Such restricted content includes anything from Nazi propaganda in Germany to depictions of violent crimes.

Facebook's user base has grown explosively to 1.55 billion people, up from 1.4 billion in the second half of last year.

Facebook says the vast majority of requests are regarding criminal cases, and the governments often requests basic subscriber information, IP addresses or account content, including people's posts online.

With respect to "valid requests relating to criminal cases," the company reported 410 requests concerning 508 accounts in Canada in the first half of 2015, with data produced 79 per cent of the time.

That represented a 47 per cent increase from 279 requests regarding 355 accounts from the Canadian government in the last half of 2014. Data was produced 58 per cent of the time during that period.

The number of requests from Canadian officials in the six-month periods in the first year Facebook , 2013, were under 200.

The bulk of government requests came from U.S. law enforcement agencies. U.S. agencies requested data from 26,579 accounts - comprising more than 60 per cent of requests globally - up from 21,731 accounts in the second half of 2014.

Content most often taken down in India, Turkey

France, Germany and Britain also made up a large per centage of the requests and had far more content restricted in 2015. Some of the content taken down in Germany, for example, may relate to Holocaust denial, Facebook said.

India and Turkey were responsible for most of the content taken down for violating local laws. India had 15,155 pieces of content restricted - nearly triple the amount in the second half of 2014 - while Turkey had 4,496, up from 3,624. The number of Facebook users in India is up nearly 70 million since June 2014, to more than 190 million users.

Governments have increasingly relied on Facebook's vast troves of user data to help investigate criminal cases, which are responsible for most of the requests, Facebook said.

"Facebook does not provide any government with 'back doors' or direct access to people's data," Facebook wrote.

Facebook, Microsoft Corp, Yahoo Inc and Alphabet Inc, formerly Google, last year began publishing details about the number of government requests for data they receive.