National security requests to Apple more than doubled over the course of 2015, according to a transparency report published today. The report lists between 1,000 and 1,249 accounts affected by national security requests in the second half of 2015, indicating that at least some private information was disclosed in each instance. That's a marked contrast from the first half of 2015, which saw between 250 and 499 accounts affected by requests. Total requests also rose from 750–999 to 1,250–1,499 over the same period.

It's unclear what might be behind the rise. Apple was restricted from reporting national security requests before 2015, a restriction that was lifted with the USA Freedom Act, so we have no earlier data to compare with today's report. As a result, it's possible that the first half of 2015 was abnormally low, or that the higher numbers have precedent in earlier years.

Still, the period coincides with increasingly vocal criticisms of Apple encryption policy from law enforcement. With the wide release of iOS 8 in September 2014, agencies lost the ability to access messages and contacts stored locally on iPhones, an issue that came to a head with the San Bernardino case earlier this year. That issue would have affected law enforcement and national security agencies alike. Still, law enforcement requests to Apple remained relatively flat over the same period, rising from 971 to 1,015 requests received.