... Case in point, something like an year ago a friend asked me to backup messages from her device. The phone was unrooted older Samsung Galaxy model, and I had really hard time breaking into the darn thing to gain access to the messages without wiping the device in the process. (when bootloader is unlocked it would wipe it, and have you ever tried rooting a device when bootloader is locked, hmm...)
Anyway, only signed and trusted applications can access the personal information storage which is root accessible only. ...