When Bluesky CEO Jay Graber took the SXSW stage this week, she managed to make fun of Mark Zuckerberg without mentioning Meta at all. Her black t-shirt was emblazoned with black text stretching across the chest and sleeves, similar to the style of a t-shirt that the billionaire founder wore at an event last year. Graber’s shirt declared in Latin, Mundus sine Caesaribus. Or, “a world without Caesars.”

On Bluesky, users expressed such excitement over Graber’s t-shirt that the platform decided to sell replicas to raise money for its developer ecosystem.

The $40 shirt available in sizes S – XL sold out in a matter of minutes.

Zuckerberg has drawn comparisons between himself and the Roman dictator Julius Caesar — the particular shirt of his that Graber is referencing said Aut Zuck aut nihil, or “Zuck or nothing.” It’s a nod to the Latin phrase Aut Caesar aut nihil, befitting of the Roman leader’s regime. (Yes, it is weird that Zuck goes out of his way to compare himself to a violent dictator).

Though it’s tiny compared to Meta’s empire, Bluesky’s decentralized, open source infrastructure imagines a form of social media where individual executives don’t hold all the power.

It creates the opportunity for any developer to contribute to the platform’s growth. So, Graber’s shirt isn’t just a petty swipe at a much larger competitor — it represents the ethos that Bluesky is trying to live up to.

“If a billionaire came in and bought Bluesky, or took it over, or if I decided tomorrow to change things in a way that people really didn’t like, then they could fork off and go on to another application,” Graber said at SXSW. “There’s already applications in the network that give you another way to view the network, or you could build a new one as well. And so that openness guarantees that there’s always the ability to move to a new alternative.”