This is controversial. Many Linux users do not use anti-virus protection at all.
Some use it because they want to be good netizens because while Windows viruses
cannot infect Linux, we can spread them to Windows users via email, etc. Others
take all security issues very seriously and harden their systems to the max.
The fact is that there are comparatively few Linux viruses and you have to be
negligent to get infected because you need root access to do much damage. If you
never log on as root this can alleviate this concern for the most part. A
typical Linux user who takes passwords seriously, who has set his or her system
up with normal security and keeps the system up to date, the chance of being
infected is statistically remote enough that most people choose to ignore the
threat. I cannot advise anyone to do this because crazy things can happen.
I am constantly on the net and I do not use an antivirus program. I have never
been infected on Linux. Nor have I heard of a Linux user being infected. This is
not to say that it can't happen. It also may mean that nobody wants to admit to
being stupid by granting permission to viruses to infect them.
I have a router that is firewalled and my computers are all firewalled. I use
anti-virus programs on my Windows machines plus programs that warn you of any
changes to the system (like Winpatrol). I take a callous approach to Windows
that you get what you ask for, so don't buy the whole good netizen thing. My
solution to viruses is simple; don't use Windows. Sounds hard, but I have seen
too many bone headed things and bailed too many people out over the years to be
overly sympathetic or to try to protect them from themselves. I will still help
friends and family, of course, but they know my feelings. To be selfish, using
Windows grates on me sufficiently that I resent being put into the position to
having to use it.
In my family, my wife and daughter use Windows XP and Vista, respectively. My
wife does not engage in dangerous behaviour on the net and I keep her system
protected and current. My daughter downloads, IMs and engages in risky
behaviour, but I have installed basic protection and Vista has a better rep than
Windows regarding security. So far, so good.
The biggest problem in trying to set up Linux anti-virus programs is that they
cannot be made to work in the background as Windows programs do without a great
deal of hassle. This makes their usefulness dubious since everything must be
scanned manually as it comes in or at regular intervals. It takes discipline
which I lack and the lack of real need to do it kills any motivation I might
have to set up dazuko to scan automatically. I have done it a couple of times,
but it was sufficiently a pain that I don't want to spend my time doing it.
Everyone has to make up their own mind about what OS to use and the level of
security that you are prepared to live with. Too much because an unwanted
intrusion and becomes more bothersome that the threat itself. Absolute security
is next to impossible. Most people choose an acceptable medium.