The most basic but often overlooked element of network security involves keeping hardware protected from theft or physical intrusion.
Corporations spend large sums of money to lock their network servers, network switches and other core network components in well-guarded facilities.
If data theft through a physical means (i.e. stealing a computer or router) is a concern, one solution is to stop storing the data locally. Online backup services can keep sensitive files stored off-site at a secure backup location so that even if local hardware is stolen or compromised, files are still secured elsewhere.