In 6 hours while we were sleeping our plan went from roughly 30 GB used in the last 28 days to just under 100GB! Checked data useage on all devices 2 iphones, 2 Ipads and a Macbook and the total data used by all of those devices totals 34GB some of which was on cable WiFi! What can explain this and how can it be stopped? Two devices were in airplane mode all night and the other two had no apps open in the background. MacBOOK has activity monitor that tracks data usage. Two devices were upgraded to IOS 9.3 yesterday. Any ideas??