Apple has decided to publish details of data requests from the US authorities.
Apple is the latest tech firm to disclose the US government requests and said it received demands for information linked to between 9,000 and 10,000 accounts or devices between December 2012 and the end of May 2013.
It said the demands included “national security matters” among other information. Microsoft and Facebook published similar numbers last week.
But Google and Twitter have said that such disclosures are not helpful.
“We have always believed that it’s important to differentiate between different types of government requests,” said a statement by Google published on Saturday.
“Lumping the two categories together would be a step back for users.”
A tweet from Twitter’s legal director, Benjamin Lee, added: “We agree… it’s important to be able to publish numbers of national security requests – including FISA [Foreign Intelligence Surveillance Act] disclosures – separately.”
Tech firms have been under pressure to disclose information about data passed to the National Security Agency (NSA) since The Guardian and Washington Post newspapers revealed the existence of PRISM – a programme giving the NSA access to user data held on the servers of tech firms including Microsoft, Yahoo, Google, Facebook, PalTalk, AOL, and Apple.
The NSA later confirmed the existence of the surveillance scheme as well as a separate phone records programme which it said had helped it thwart terrorist plots in the US and more than 20 other countries.
However, privacy activists and some politicians have raised concerns that the efforts went beyond what was intended under powers granted by the Patriot Act following the 11 September 2001 terror attacks.
Following the revelations, several of the tech firms involved said they had asked the US government to allow them to disclose information which would help them address concern about the scale of information that had been handed over.
On Friday, Facebook and Microsoft announced they had been given permission to reveal the number of data requests from US officials in aggregate, and Apple has now followed with its own statement.
“We first heard of the government’s <<PRISM>> program when news organizations asked us about it on June 6,” it said.
“We do not provide any government agency with direct access to our servers, and any government agency requesting customer content must get a court order.”
Facebook added that between 1 December 2012 and 31 May 2013 it received between 4,000 and 5,000 requests from US law enforcement for customer data, involving between 9,000 and 10,000 accounts or devices. It did not say with how many it had complied.
It said the “common form of request” came from police who were investigating crimes such as robberies, trying to find missing children and patients with Alzheimer’s disease, or hoping to prevent suicides.
It noted that it would not have been able to decode encrypted conversations which took place over its iMessage or Facetime chat software on behalf of the authorities, nor did it store “identifiable” data related to Apple Map searches or requests made to its voice-controlled Siri service.
“Regardless of the circumstances, our legal team conducts an evaluation of each request and, only if appropriate, we retrieve and deliver the narrowest possible set of information to the authorities,” it added.