Why is my internet data usage high when not home?

If people only knew the level of automatic spyware built into their Googled and iPhone type phones, and those phones upload that data via whatever means it has readily available (including your WiFi).  Your "normie" phone listens to everything you say, everything you do, every place you go, it sniffs the bluetooth environment you are in for other phones and wireless devices.  It uploads your days activities in the middle of the night, to include pictures, texts, locations, your contact list, who you were within 32 feet of at any point during the day, if its an iPhone it sends it to both the iCloud and to the Google servers.  If you have Facebook installed, it sends all or most of that same data to Facebook.  If you tweet, instagram or use classic social media it captures that data and sends it to the cloud based services for them to mine your metadata and place you into cohort groups for further monitoring - this monitoring is then sold to anyone who might be interested in knowing your interests, and those groups then target you for advertising or other nefarious purposes.  Ever wonder why new modern cell phones don't have easily removable batteries?  Because even when your phone is "off" it is still active.  The only way to truly silence it is to remove the battery or turn it off and place it in a Faraday bag.  Then take a look at your 4am data (midnight - 6am) and you'll discover that your phone is sending hundreds of megabytes (more than likely gigabytes of data) in the middle of the night while you are sleeping.  Get a De-Googled phone and this problem goes away - as long as you don't use social media on your De-Googled phone.