Kaspersky Anti-Virus Mac

Well, I highly disagree with this user's review. Internet Security Barrier X6 can really screw up your Mac's Internet experience - monitors too many activities, causing extreme slow downs & possible system crashes. Kapersky on the other hand is low over head (you shouldn't notice any degradation in your Mac's performance) it's just looking for parasites that you might transmit to your Windows brethren. I think this reviewers software issues stemmed from existing problems and installing Karpersky was the last straw.

I also prefer Karpersky for my Windows computers due to low overhead but as any Virus protector on Windows it can become a nuisance with popups and other notices.

For Mac internet security I recommend: Little Snitch (let's you know when resident software is making internet inquiries, Kapersky to protect Windows users from parasites when you exchange data (email, ftp, etc....). and Apple's firewall to intercept incoming meanies.
Norton sucked on OS X.

I've been a Mac support professional for the last 30 years and I am not affiliated with any of the companies mentioned in this post.