There is a HUGE controversy about Adblock plus. One blogger uncovered some of their business methods. They have Mafia like structures and extort businesses. Unfortunately it's only in German and I have yet to find an English site report about it.
I never appreciated the difference or history of the Adblock and Adblock Plus plugins. I'm currently removing ABP from all my desktops and laptops in favour of Adblock Edge. Thanks.
To Adblock? I use a system level HTTP proxy (Glimmerblocker [1] on OS X, Privoxy elsewhere [2]) because I don't want to encounter ads in e.g. my RSS reader.
Main article (very detailed):
http://www.mobilegeeks.de/adblock-plus-undercover-einblicke-...
They've been trying to cover up their methods and simply lied about it. Stay away from Adblock Plus.
Some shorter article:
http://www.heise.de/newsticker/meldung/Adblock-Plus-Weitere-...