Facetime & Text & Email Hack
The history of your calls and messages will be stored in your device but in an encrypted manner which even apple doesn't share or record them in iCloud. So FaceTime and iMessage are safe. But if you give your Apple ID and password to someone else, than can have a hand over the messages. So you can protect them by enabling Two step Verification for your device and by Creating App-Specific Passwords. 

Everything about Two step verification
https://support.apple.com/en-in/HT204152

Everything about App-Specific Passwords
https://support.apple.com/en-in/HT204152