Many sites do this, but the problem with Adblock that most people are not happy about is that it AUTOMATICALLY blocks everything. You have to whitelist, and most people just turn adblock on and leave it be... If it was required to blacklist instead of whitelist it'd be better. Many sites with non-intrusive ads are being blocked because of this and that's detrimental. It's already hurting many businesses to the point that soon content online is gonna be behind a paywall and you're gonna end up having to pay $5/mo for every site you want to view.
I, as a user, wouldn't be happy having to blacklist all sites.
I won't pay a monthly fee for most sites, because I read a little on a lot of sites - I don't mind paying a 1 penny per article fee if it is convinient.
Unless you visit some very shady sites, having a auto-blacklist isn't needed, and a whitelist is best to keep both parties happy. And if Adblock continues to grow the way it does, the second route is gonna be what happens, nobody is gonna be able to make any money off advertising therefore they'll have to take other routes to pay for their servers to provide you with your content free of charge.
