We all know the golden rule only run one firewall and anti-virus or one security suites. Well the Webroot/Prevx team kind of changed that. They created a cloud security suite designed to run alongside your current setup. Already sounds like over kill.
But I guess it comes down to matter of opinion.I did play around with it for a few days and didn't notice any slowdowns or heavy ram usage. The most I saw it use was no more than five megs. I personally bombarded the hell out of in VM Ware against variety zero days, exploits, and phishing sites. It didn't do all that bad by itself.
This might be something to look into if you know some who needs a little help staying safe.
http://www.wilderssecurity.com/showthread.php?t=305134