You have to install Konqueror and configure adblock from there. Then akregator uses the same config. Today, konqueror usually isn't installed by default, that's one problem. I don't think most users realise that you can use adblock inside akregator. Just to confuse the user further, requonk, that is more likely to be installed by default, has it's own config, that works just for it self, independent from konqueror. Expected behaviour: You should be able to configure adblocking for akregator from inside akregator. Maybe, also have a central place to configure adblocking for all KDE applications. in system setting? Network Settings? the same widget accessible from the applications and from settings. In any case, something should exist inside akregators config settings mentioning adblocking.
Now we use qtwebkit so I added some config as in kmail. It's in progress (for 5.2)
Fixed in 5.2