Microsoft tries to thread the needle of transparency by telling its consuming audience as much about governmental collection of data as possible. Toward that end Microsoft releases a biannual transparency report.
Within the latest transparency release Microsoft reports in the first half of 2016 they received a massive increase in FISA orders; primarily from U.S. governmental agencies.
• “For the latest Foreign Intelligence Surveillance Act (FISA) data reported, Microsoft received 1,000-1,499 FISA orders seeking content disclosures affecting 12,000-12,499 accounts, compared to the 0-499 FISA orders seeking disclosure of content impacting 17,500-17,999 accounts reported for the previous period.
We received 0-499 National Security Letters in the latest reporting period, which remains unchanged from the previous period.” (link)
Why would there be such a significant spike in FISA orders during the first six months of 2016?
Due to legal compliance restrictions Microsoft cannot divulge the actual number of FISA Court Orders, only the range. As you can see there was at least a doubling of requests (Prior: 0-499 ~vs~ Now: 1,000-1,499) perhaps much more.
However, simultaneous to the increase in the number of FISA orders, the requests were on fewer accounts. So FISA using agencies were seeking more total data but on a smaller number of accounts.