Yes you did miss something there. Open source means that anyone can patch the hole up. And they do. Open source means tha security holes are faster discovered and patched. The other thing with viruses is the diversity of linux distributions. As some programs don't work on all distributions without proper midifications, how do you expect viruses to work on every machine. Thus virus makers(who ever they are and why they do it I don't know) would have to be damn good to make a virus that would spread so quickly through Linux than it does through windows(because windows are all the same). One other thing I saw at www.f-prot.com
is that W32 viruses are as many as you want. And UNIX viruses are only 2 recorded by F-prot and that the las one was recorded 2 years ago. Most viruses are made executables (exe files). You can't run an exe file on Linux unless you want to. But don't be fooled into thinking that you can't get a virus. It just can't harm you.