Like a lot of tech fans, I absolutely love the Mr. Robot TV show, but it seems Mozilla overestimated how much it could get away with when promoting the series. The company has been forced to backtrack after a browser extension it covertly added to Firefox resulted in user outrage.

Mozilla boasts that its new Firefox Quantum browser is twice as fast as Firefox was a year ago and often faster than Chrome, but users were shocked after a plug-in appeared last week that they didn’t install. The Looking Glass extension came with nothing more than a description reading “MY REALITY IS DIFFERENT TO YOURS.”

Understandably, many feared that a form of malware had infected their machines. “I have no idea what it is or where it came from. I freaked out a bit and uninstalled it immediately,” wrote one Redditor. But it turned out that Mozilla had sneakily added the extension to Firefox as a way of promoting an augmented reality game to “further your immersion into the Mr. Robot universe.”

The extension had to be specifically enabled, at which point it would make minor changes to specific websites, leaving clues for players of the Mr. Robot ARG.

Somewhat ironically, Mozilla says it added the extension as a way of increasing awareness of user privacy. “The Mr. Robot series centers around the theme of online privacy and security,” the company explained. “One of the 10 guiding principles of Mozilla’s mission is that individuals’ security and privacy on the internet are fundamental and must not be treated as optional. The more people know about what information they are sharing online, the more they can protect their privacy.”

But the plan backfired. To add the extension, Mozilla leveraged a feature used for Firefox testing and data collection—primarily a method of addressing bugs and making improvements to the browser. Many saw this as the tool being misused for advertising purposes and have now disabled it. The revelation that Mozilla can distribute add-ons without user permission or knowledge hasn’t been well received, either.

In response to the outcry, Mozilla has wisely decided to stop placing the extension in people's browsers; instead, it is now available in Firefox’s add-on store.

“Our goal with the custom experience we created with Mr. Robot was to engage our users in a fun and unique way,” Mozilla’s chief marketing officer, Jascha Kaykas-Wolff, told Gizmodo. “Real engagement also means listening to feedback. And so while the web extension/add-on that was sent out to Firefox users never collected any data, and had to be explicitly enabled by users playing the game before it would affect any web content, we heard from some of our users that the experience we created caused confusion.”

“As a result we will be moving the Looking Glass Add-on to our Add-On store within the next 24 hours so Mr. Robot fans can continue to solve the puzzle and the source can be viewed in a public repository.”

Mozilla’s unsolicited ‘gift’ to its users has parallels with Apple and its U2 promo disaster. Cupertino’s decision to automatically download U2’s album onto half a billion iTunes users’ accounts in 2014 was such a misguided piece of PR that it made our Most Awkward Moments in Tech feature.