In fact, Interactive Advertising Bureau (IAB) SVP and general counsel Mike Zaneis tweeted that the default is a "nuclear first strike against ad industry."
Although some responded that Apple's Safari really started the anti-third party cookie battle.
"The new Firefox policy is a slightly relaxed version of the Safari policy," said Jonathan Mayer, a researcher at Stanford who wrote an in-depth post about what the new policy means.
Chrome and Internet Explorer currently allow cookies, although Microsoft recently drew the ire of the advertising industry when it created a default do not track setting on IE 10 without any warning to its ad partners.
While Firefox users can already manually disable cookies, the new default cookies-free setting is expected to premier with Firefox 22, Mayer says. We're currently on Firefox 19. CNET writes that this might be rolled out as early as April 5.
And while the ad world is recoiling, privacy advocates can settle one more move to lock advertisers out of users' web experience.
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