I heard Linus Torvalds who developed the Linux kernel discuss his own personal
computer and he sounded paranoid about giving people access to his computer
because he develops on it. Security is a major concern for him. He uses a
firewall and closes most ports usually used by others. This is one extreme and
the other is somebody who takes no precautions.

Linux can be tailored to anyone's needs. It is the most flexible OS there is. It
just depends on what you are trying to do. Total security is possible, but it
means that you lose connectivity, too. You must make compromises and it is all
about what you want to do with your computer and how willing you are to take
risks and what extremes you are willing to go to to manage those risks.