Seems like this is what they're referring to:
> Their publishers had sought damages, but said their motivation
> was to challenge the software provider's wider business model.
> While AdBlock Plus offers its web browser add-on to the public
> for free, it makes money by operating a "white list" of adverts that
> it allows to get through its filters.
For example:
> In February, the Financial Times reported that one unnamed
> media company had said it had been asked to pass on the
> equivalent of 30% of the extra revenues it would have made
> by having ads on its platform unblocked.