[AgentZero]

I use Comodo as a firewall, and haven't bothered with anti-virus in some time. I've used Norton, Mcafee, AVG & Kapersky at various points, and as far as I can remember they've detected two "viruses" though both turned out to be false positives. So now I just don't bother. I run online tests now & then and always come up clean. I stopped bothering with anti-spyware/adware recently as well, after I realized that all the "spyware" that S&D and AdAware were coming up with was all just cookies from the likes of Doubleclick.

And if Doubleclick wants to know what I'm Googling that badly, I don't really care enough to stop them. I'm sure they'll appreciate the irony of seeing "Ad blocking extensions" in there somewhere.