Traditionally, a user’s view of a computer system is like an onion. Explain why this concept is outdated and draw a new diagram based on the concept proposed in this book Computer firewalls are used...

Traditionally, a user’s view of a computer system is like an onion. Explain why this concept is outdated and draw a new diagram based on the concept proposed in this book

Computer firewalls are used to protect computer from data loss. Why firewalls can not guarantee data security?