Herd immunity has nothing to do with computer viruses. This analogy simply doesn’t make sense.
Paying for Norton AV for all subscribers is a selling point for them, I assume. It’s not necessary that Norton actually help the subscribers, only that potential subscribers believe it will, and therefore choose that provider over another.
That said, it probably does help the typical subscriber, at least occasionally. And if it prevents even a few customers from getting infected with bot-net software and eating up bandwith with spam (or whatever), it might be worth the investment.
Sure it does: the less computers are infected by viruses, the less likely they are to send an infected file to an unprotected computer.
Where the argument fails is that it doesn’t matter why you don’t spread the infection, just so long as you don’t. Patty is just as much a beneficiary of my good computing practice as I am of his antivirus software.
Can you elaborate on this a bit? If you’re talking about Norton and McAfee being resource hogs, you’re talking about bad implementation of a concept, not a bad concept itself.
Acknowledged in the post you quoted. Nothing is perfect - not being perfect does not equal useless or detrimental.
As far as I can tell, all of the people who have described methods by which you can carefully tiptoe around threats (but without AV software) have described incomplete, inadequate methods.
I think they are necessarily resource hogs. They intercept so much of what the user does. When we trialled the various replacements for our previous antivirus solution, Symantec Antivirus, all the triallists complained that their PCs ran slower. On the other hand, SAV didn’t actually detect much of the malware written in the last five years. And the anti-malware solution we eventually replaced it with still doesn’t detect everything. It was a compromise between actually being useful and not hobbling the PCs too much.
My solution is: Avoid using an admin account. I didn’t say it was a perfect method, and some things are still fiddly under it, but I don’t think it’s tiptoeing. It is a general approach that meets my claim of being “achievable by regular people and not just geeks”.
If your computer runs slow due to having good AV software then you might need more hard drive or a faster connection. I run two all the time and do not notice any slowing at all? I have a two year old computer and a good broadband connection. if my computer is a little slow it is because my upstairs neighbors are probably using their laptop off of my connection.
My poor Mom has had two very expensive visits by the Geek Squad to fix her computer after not buying AV software. At somewhere are around 200 dollars a fix I made her get Norton and had the Geek Squad install it. She also had something put on her laptop so people couldn’t steal her signal? She has been fine ever since. Well unless she forgets her password again. 
I don’t know what you mean by not using an admin account? You mean just use your neighbors bandwidth? Or go to a cyber café with a lap top?
One simple thing to do is not use the default user for your PC because that user can change anything about the system. You need to setup another user account and use that and do not give the other account admin access. That alone will cut out a lot of problems.
Of course Symantec is slow. That’s why people recommend faster alternatives. And while Limited accounts make it easier to remove malware, I’ve yet to see any that was actually stopped by it. Most malware is not completely dependent on running in an Admin account
And the claim that non-techies can use it is false. Just see Perciful’s comment below. It generally takes a bit of work to actually set up a limited account to where it is usable. And, since some settings require administrator access, you have to know how to switch your account back and forth.
If you’re really worried about programs, get Process Guard. The only slowness you’ll get is having to confirm that a program is required to run. It’s funny seeing a virus ask permission to run.
I didn’t say anything about AV effectiveness. I meant that people that “know” they’re not infected, with or without AV, are wrong.
My experience differs - I’ve certainly seen some of the more popular AV packages hog the resources on a system so as to nearly cripple it, and of course anything that does anything needs to consume resources, but I don’t find all of them to be exceptionally burdensome on the system.
Actually, that’s the first decent non-AV suggestion I’ve seen in this thread (if you or anyone else mentioned this earlier, I missed it). Still, limited user account plus AV should be more secure than limited user account without (although my son still managed to get a trojan on his PC with a limited account and AV and anti-spyware software running - so as we both seem to agree, perfect safety isn’t possible).
From the linked Wikipedia article:
This simply isn’t a real limitation for computer viruses. A single infected computer does not have to get lucky in order to continue the chain of infection. It will, instead, proactively attempt to infect as many other computers as possible (or as practical without drawing attention to itself). The probability of a computer on the internet being attacked is not dependent on the number of individuals running AV software. The probability of a computer on the internet being attacked can safely be assumed to be 1.
Harddrive space and internet speed have nothing to do with how quickly AV software runs on a computer.
Only if you assume they mean absolute philosophical certainty. If you take significant precautions against getting infected, and your computer is showing no symptoms whatsoever, and your router logs show no unusual activity, and a scan of your computer using multiple AV / anti-rootkit / anti-malware software packages (run from bootable read-only media, of course) come up clean, then you have very good reason to believe that your computer is not infected.
Up until a year or two ago, I would’ve said that no, with smart browsing, you can avoid the need for anti-virus. But recently I’ve seen my anti-virus pop up and block a lot of stuff it’s been detecting from flash ads (including, for awhile, ones on this site - some ad companies just don’t keep a tight enough lid on their users). Maybe they’re minor, but I wouldn’t want to take the risk.
I don’t really understand the convenience/security distinction. Sure, maybe if you’re using some crappy bloated antivirus like Norton that eats up all your memory, but it’s not that big of a deal to just run a smaller, slimmer antivirus in the background.