Web developers reallyhated Internet Explorer 6.

YouTube’s developers were so tired of dealing with the outdated Microsoft browser back in 2009 that they devised a plan to kill it, according to a postwritten by ex-YouTube engineer Chris Zacharias.

The plot was carried out without the permission of YouTube’s parent company, Google, says Zacharias who worked at the company from 2007 to 2010.

“IE6 had been the bane of our web development team’s existence,” writes the ex-YouTube engineer who is just now sharing the story about how IE6 met its demise on his website. “At least one to two weeks every major sprint cycle had to be dedicated to fixing new UI that was breaking in IE6.”

A decade ago, around 25 percent of internet users were still surfing the web using Internet Explorer 6 even though more modern web browsers like Firefox, Chrome, and even IE8 existed. According to Zacharias, around 18 percent of YouTube’s own audience visited the site using IE6, forcing developers to maintain support for the browser.

Tired of dealing with the web browser’s constant crashing, security issues, and incompatibility with modern internet technologies, the team of engineers went rogue and decided to roll out a banner across the YouTube platform with a message only visible to IE6 users.

“We will be phasing out support for your browser soon. Please upgrade to one of these more modern browsers,” said the banner, which included links to download the latest versions of Chrome, Firefox, and IE8.

The YouTube engineers were able to launch the banner thanks to a “specialized permission set” that they created “to cement their authority over the YouTube codebase” after Google purchasedthe company in 2006. These permissions gave early YouTube employees “the ability to completely bypass the new Google-oriented code enforcement policies,” according to Zacharias.

The YouTube team had no power to actually end IE 6 support on their own. The plan was simply to deploy a scare tactic meant to lower the web browser’s market share.

Other Google product teams saw the banner and assumed YouTube received permission from management to deploy the message. Quick to also rid their lives of IE6, these engineers rolled out their own version of the banner urging users to upgrade to modern web browsers across Google’s services.

“Once [management] realized what had happened, they begrudgingly arrived at the conclusion that the ends had justified the means,” writes Zacharias.

The mission was a success.

“Within one month, our YouTube IE6 user base was cut in half and over 10% of global IE6 traffic had dropped off while all other browsers increased in corresponding amounts,” says Zacharias. “The results were better than our web development team had ever intended.”

By March 2010, Google officially ended supportfor IE6 across all of its products. Other tech companies followedits lead. Usage of IE6 in the U.S. droppedto less than one percent by 2012.

Unfortunately, while Microsoft officially killed Internet Explorer in 2015, it stillcauses issuesfor its users to this day. Thankfully for YouTube’s engineers, it’s not their problem anymore.