If you’re not paranoid on the Internet, you’re in trouble

It’s not that everyone on the Internet is trying to attack you, but there’s always someone who wants to break into your system. Even if you think you have nothing of value, someone wants to own your computer. And you won’t realize the value of what you have until someone else has it. That’s just human nature.

Absolute OpenBSD: UNIX for the practical paranoid / Michael W. Lucas.