Jay Graber wears her distaste for tech billionaires on her sleeve—literally. The Bluesky CEO donned a shirt with the Latin phrase “mundus sine caesaribus,” which translates to “a world without Caesars,” while speaking at SXSW today (March 10) in Austin. The move constituted a subtle jab at Meta (META)’s Mark Zuckerberg, who in September wore a similar top reading “aut Zuck aut nihil,” a twist on the phrase “either Caesar or nothing” that replaces the Roman emperor with the Meta CEO.

Bluesky is growing in popularity, with upwards of 32 million users, as social media users grow upset with billionaire-owned platforms, particularly Elon Musk’s X. Bluesky’s interface is strikingly similar to that of X. But according to Graber, the parallels stop there. Its customizable features allow users to opt out of particular feeds or conversations, a move that supports an “anti-toxic experience” for users, she said. Initially incubated in 2019 by Twitter under its former CEO Jack Dorsey, Bluesky launched two years later as an independent company.

Bluesky’s decentralized, open-source network also makes it billionaire-proof, said Graber, as users who decide to leave can take their followers with them or even create an entirely new network. “The fact that users have that choice means we’re incentivized to keep serving [them],” she explained. “If a billionaire came in and bought Bluesky and took it over, or I decided tomorrow to change things in a way that people didn’t really like, then they could fork off and go on to other applications.”