Randall Rothenburg, president and CEO of the Interactive Advertising Bureau, has used his opening keynote speech at the IAB Summit to accuse popular ad blocking firm Adblock Plus of being an “unethical, immoral, mendacious coven of techie wannabes”.

Rothenburg went on to call the firm an “old-fashioned extortion racket” and claim that they are “stealing from publishers, subverting freedom of the press, operating a business model predicated on censorship of content, and ultimately forcing consuemrs to pay more money for less – and less diverse – information.”

The comments came as a reaction to Adblock Plus complaints that it had been “disinvited” from the annual summit for no reason, having attended the conference without incident last year. Rothenburg claimed that the companys online registration was cancelled and they had never been invited in the first place. Rothenburgs speech went on to attack ad blocking providers in more general terms, stating that “many of their business models are undoubtedly illegal”.

He also singled out Shine, which blocks ads at an ISP-level, and said that such practices violated net neutrality practices. Shines CEO, Roi Carthy, hit back the same day, calling the IAB irrelevant in a piece written for Advertising Age titled “Consumers Must Look Elsewhere Than the IAB for Protection”. Shine has previously publicly attacked the IAB, taking out a full page ad in the Financial Times to criticise the industry body last year.

The IAB has discussed the need to recognise the forces driving consumers to adopt ad blocking the past, and currently encourages advertisers, publishers and marketers to adopt its LEAN best practice principles in an effort to stop the rising numbers of consumers making use of ad blocking technology.