Does Linux have viruses?

[Conrad Newton <conrad.newton@broadpark.no>]

I suppose this is not really the right list for this question, but it is
not really wrong either, because I am looking for an answer that is
suitable for teachers and students---not advanced computer professionals
like yourselves . . .

I have been studying this problem, and trying to understand what can
be honestly said, ignoring all ideology.

While it is clear that it is *much easier* to write viruses for Windows,
it does not seem altogether *impossible* that it could be done for
Linux, too.  Unfortunately, "much easier" is not easy to quantify, and
therefore open to dispute!

Of course I would like to make a strong statement, but I also want
to be truthful.  Can anyone point me in the direction of
well-formulated discussions of this problem?  

Up to now, the only formulation that I find reasonably satisfing is the
following:

   Ask a Linux user when he or she last had a virus, and you will
   encounter only confusion:  although security experts agree that Linux
   _could_ have viruses (in theory), in practice I have never met a
   Linux user who suffered from one.

This seems a little weak, but at least it is honest.  Many of the more
detailed discussions are completely unusable.

Thanks in advance,

Conrad