With the release of iOS 9, Apple has triggered a crisis among Web developers and publishers. The root of that crisis is the new operating system’s ability to block ads on mobile websites. (LifeHacker provides an excellent breakdown of how to enable the feature, including a list of third-party ad blockers that work in conjunction with it.) Blocked ads equal less revenue for those websites that depend on them, potentially putting a number of content-producers in a very bad spot. Or as LifeHacker put it, in the very same article where it describes how to enable iOS 9’s ad-blocking abilities: “Unless you want to see all your favorite sites go out of business, we humbly remind you to whitelist the sites you like.” Over at Daring Fireball, John Gruber had a harsh reaction to Web developers’ and publishers’ complaints:

The coming reckoning for publishers is not ‘because of Apple.’ It’s because of the choices the publishers themselves made, years ago, to allow themselves to become dependent on user-hostile ad networks that slow down the Web, waste precious device battery life, and invade our privacy. Apple has simply enabled us, the users who are fed up with this crap, to do something about it.

In any case, the apocalypse hasn’t quite come for those who depend on revenue from website ads: While millions of people will use iOS 9, millions more will continue to rely on other platforms to absorb their content—provided, of course, those platforms don’t decide to follow Apple’s lead. Tech pros who are worried about their website revenue can run analytics to see how much of their audience arrives via iOS, and perhaps consider flipping the switch on any long-shelved plans to generate money in other ways. While the Web-ad market isn’t set to implode in the near future, it’s clear that some sort of inflection point is on the horizon.