GoKawiilMy Wireshark test of Firefox 148 showed that its AI kill switch disables generative features, but leaves telemetry and advertising untouched. Six months later, Mozilla’s CEO has called the switch perhaps the most important AI feature of all. I retested it in Firefox 155.
Firefox promises to protect users from companies spying on their clicks during onboarding. The AI controls are not mentioned anywhere in that flow. Screenshot: Marius Quabeck.
My first test of Firefox’s AI kill switch apparently reached readers I had not expected. I was told that the article made its way into Mozilla’s internal Slack and was discussed there. The verdict: a “hit piece.” The fact that my previous Firefox article had been featured on the cover of the US edition of Linux Magazine probably did not help. Anyone who read it will know that its core consisted of preferences, host lists, and timestamps. The reaction is nevertheless unsurprising. It is a familiar response when someone holds Mozilla’s own behavior up to the company. It is not my fault if Mozilla does not like what my tests revealed about its own behavior.
My previous Firefox article was featured on the cover of the US edition of Linux Magazine, Issue 309 (August 2026). Photo: Marius Quabeck.
To be clear, I know that the AI kill switch does not claim to disable telemetry or advertising. I tested both again because they were part of my previous investigation, and because the response to that article showed why the distinction matters. Many readers told me they had no idea how much tracking Firefox performs in the first place. Others had genuinely understood the AI kill switch as a universal off switch for AI, telemetry, and advertising. Here is an idea, Mozilla: either expand the existing switch or put a second one next to it.
Six months later, Mozilla’s leadership sounds different. On August 25, CEO Anthony Enzor-DeMeo published an essay with the remarkable title “Trust is earned. Consent is asked. AI skipped both.” Reading it is disorienting in places: a message from the ivory tower that reaches exactly the conclusion critics had reached months earlier.
Humility as strategy
Enzor-DeMeo begins with his first day as CEO in December 2025. In interviews around his appointment, he had talked about AI in the browser; after all, the features were optional. Then came the backlash. “It was a gut punch. Frankly, I deserved it,” he writes. “I said the right words and still missed the message.” One of his first decisions as CEO was therefore not to launch another AI feature, but to build the switch that turns them all off. He clearly dislikes the name “kill switch,” preferring AI Controls. He says he accelerated the project partly for personal reasons: he, too, was tired of AI popping up everywhere.
He had been proud, he writes, that Mozilla could let users decide “how they AI.” Then the feature shipped, followed by the sentence to which the essay gives a paragraph of its own: “Almost nobody used it.” In the months after release, roughly one percent of users reportedly switched off all AI and three percent disabled individual features.
The CEO’s interpretation is that AI has no fixed definition. Translation is machine learning of the kind that has existed for decades; generative AI is only one subset. Most users left translation enabled while tending to reject the generative features. That is not a free pass, he concedes, citing Pew Research: about half of US adults now use AI chatbots, yet 59 percent do not trust US companies to develop AI responsibly. His conclusion is that, in a world where companies force AI on their users, Firefox’s strongest argument is “choice and agency.” The final line has the makings of a poster: “The most important AI feature may be the ability to turn it off.”
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