I fear the use of the word "virus" these days are a threat in itself, as it makes people relax their overall security sense. Even on Windows, the real threat isn't viruses any more.

There are lots of exploits to worry about on Linux as well as on Windows. Server logs are full of probes for weaknesses in PhpMyAdmin, Gallery2, PhpBB. Probes on SSH exploits are also common. And where does the term "root kit" come from, you might ask yourself, as there is no root user in Windows? While Windows is easier to infect, Linux machines are more attractive because they're often servers, internet hubs, where you want to use their resources, take over their services, has more interesting content, whatnot.

At home, I have a Linux based router. It is old now, and I worry that the outdated linux packages have known issues.

Thankfully, IPTables seems to do a commendable job on Linux, but even so, for a desktop Linux machine I would have liked a ZoneAlarm-like GUI on top, to set rules and see activity. And yes, Antivirus. Although there aren't many Linux viruses running around yet, I'd still like to notice if there were other machines on my network sending out infected traffic.

But on any Linux desktop as well as on any Windows desktop, I'd really feel better if there was a hardware firewall (ie. router modem) between me and the internet.

I haven't been bothered with what-actually-is-viruses on my computers since, well honestly not since MS DOS disk swapping. But other malware, that's always a real threat.