[blueskin_]

I doubt even many users will be stupid enough to not only click some random fake error ad, but follow the advice of a dodgy site. Almost everyone who has adblock installed it knowingly, wanting the effect and knowing what it does.

[Perseids]

What about all those friends and relatives we do tech support for. Most of them have not installed their addons on their own.

[blueskin_]

Some but not all. I've been mildly surprised to see family members running chrome (yes, I know, privacy issues with chrome, but better than IE...) or firefox with an ad blocker before.