Actually, that's a good point - it was always the case that corporates had firewalls, but few home users had them due to cost. Now you can pick up an old 486 PC for free and run a prefectly servicable firewall on it. Although having a dedicated firewall is not a silver bullet, it will really help and is very easy. There are free fw installs for download, some of which do not even need hard drives (tiny firewall)