I don’t have a heck of a lot to say about botnets, as I have a firewall doing NAT translation in front of my machines, and software-based firewalls and anti-virus protection on all machines. And I receive little or no spam, so in essence, I don’t have experience with botnets and what kind of damage they can do.
But there is a big trojan attack building zombied computer networks across the world right now, and security experts are warning about growing trojan threats.
If you don’t already have protections in place yet, I suggest you get some now.