When Apple said it was going to allow ad blocking on the iPhone version of its web browser last September, it escalated a conflict that had been building in the digital economy for years.
Programs such as Adblock Plus, AdFender and Popup Blocker Pro have long claimed to protect consumers from intrusive web ads that slow down our browsers and hoover up personal data.
Around 200 million people globally are estimated to use such apps. But for businesses that depend on web advertising, ad blockers could cost an estimated $21.8bn (£15bn) in lost revenue a year. While some dispute this figure, most in the industry agree that ad blockers threaten publishers’ ability to provide content free at the point of use. Now publishers and advertisers are fighting back; the battle of the blockers is heating up.
To find out how read BBC.co.uk