More Data on Privacy, but Picture Is No Clearer

Technology companies, the custodians of reams of personal data from hundreds of millions of people around the world, have been under fire after recent revelations that they secretly handed over customer information, including e-mails, in response to requests by the federal government made in the name of national security. Now, one by one, the companies are putting out data intended to reassure their users that the government gets information on just a tiny number of people. But rather than provide clarity, some of the disclosures have left many questions unanswered.

How many of the requests were from investigators seeking to sniff out the next terrorist? The companies said they were not allowed to say, although they noted that the requests were commonly related to things like local police investigations and searches for missing children. That continuing restriction prompted both Google and Twitter to say they would not publish similar data until they could separate national security requests from the rest.