Mariann Hardey’s father died unexpectedly a little over a decade ago. But he lives on through his Twitter account. It only has 42 followers, and it was locked by Hardey’s father so no one but those 42 people can see it. And with a common first name and surname-based username, it’s likely a sought-after bit of online real estate.

“I regularly check in with him over social media,” says Hardey, a sociology professor at Durham Business School in the UK. The profile—the last tweet of which praised Hardey for her braveness in getting a wisdom tooth removed—is doubly important to the professor because its profile picture is a kitten, Penny, that Hardey’s family lost last year.

That could soon change. Twitter CEO Elon Musk has announced a purge of dormant accounts—having previously claimed there are 1.5 billion on the platform. As a result, Hardey’s father’s Twitter account, which hasn’t been updated since March 14, 2012, could soon be wiped from the internet. “He has a granddaughter now who he has never met, and his social media quips and content show her who he was, and what we meant to each other,” Hardey says. “Social media is about connections.”

It’s a move that, as with so much on Musk’s Twitter, could be chaotic. Single-word or -letter Twitter accounts, long-dormant profiles of celebrities who have died, like Linkin Park’s Chester Bennington, and cherished brands that have abandoned Twitter or were taken over by squatters, such as @Nintendo3DS, could all be taken over by new owners.

“It might sound like the closure of a few dormant accounts, but the consequence is the reckless endangerment of enormous swathes of evidence, all to create a synthetic market in usernames,” says William Kilbride, executive director of the Digital Preservation Coalition. Kilbride compares Musk’s decision to “burning the public record to sell personalized number plates.” It’s just the latest example of big platforms making changes to the permanence of the content hosted on their platforms, after Imgur and Tumblr switched policy on the hosting of pornographic material, removing huge swathes of their content. Musk has said purged accounts will be “archived,” without providing more information.

The planned purge is especially problematic as Twitter is seen by many, including Musk himself, as a de facto public square of the internet—vast swathes of which could soon vanish. “When you have these gigantic global systems, changes have to be instituted very carefully,” says Mar Hicks, associate professor of the history of technology at Illinois Institute of Technology.

It’s one of the perils of private ownership of public platforms that act as quasi-utilities. “Twitter has been relatively small, but it’s had an outsized influence, because it’s the place where journalists go,” Hicks says. “For it to descend into chaos, in multiple ways, is really dangerous.” One example of what could potentially be lost if the plan goes ahead: the loss (or repurposing) of Syrian activist Raed Fares, whose account—and record of human rights abuses—remains crystallized in amber following his November 2018 assassination.