You can prevent data leakage by overwriting the data stored on the machine.
There are two kinds of overwriting as follows:
Auto Erase Memory
When you edit or delete data on the machine's hard disk, the data is automatically erased by overwriting so that unnecessary data is not retained. For details, see Auto Erase Memory.
Erase All Memory
All data stored on the machine's hard disk is erased by overwriting over it. The device settings stored on the machine's memory are initialized. Execute this to erase all data and settings when you relocate or dispose of the machine. For details, see Erase All Memory.