At SXSW, Bluesky CEO Jay Graber pokes fun at Mark Zuckerberg with Latin phrase T-shirt

When Bluesky CEO Jay Graber walked on stage at SXSW 2025 for her keynote discussion, she wore a large black T-shirt with her hair pulled back into a bun. At first glance, it might appear as though she’s following the same playbook that so many women in tech leadership have played before: downplaying her femininity to be taken seriously.

The truth is way more interesting than that. What might look like your average black T-shirt is a subtle, yet clear swipe at Mark Zuckerberg, a CEO who represents everything that Bluesky is trying to work against as an open source social network.

The Meta founder and CEO has directly compared himself to the Roman emperor Julius Caesar. His own shirt declared Aut Zuck aut nihil, which is a play on the Latin phrase aut Caesar aut nihil: “Either Caesar or nothing.”

Graber’s shirt — which directly copies the style of a shirt that Zuckerberg wore onstage recently — says Mundus sine caesaribus. Or, “a world without Caesars.”

With the way Bluesky is designed, Graber is certainly putting her money where her mouth (or shirt) is. As a decentralized social network built upon an open source framework, Bluesky differs from legacy platforms like Facebook in that users have a direct, transparent window into how the platform is being built.

“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 explained 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.”

Meanwhile, Meta has alienated users by interfering in how people experience its platforms, and Bluesky has directly benefitted from that. After Meta pushed controversial updates like training its AI on public user posts, or culling its third-party fact-checking programs, Bluesky experienced bursts of user growth.

Still, Bluesky has a long way to go if it wants to topple the Roman Empire of Meta. While Graber’s platform is closing in on 33 million total users, Meta has 3.35 billion daily active users across all of its products: Instagram, WhatsApp, and Facebook. For Meta, that’s around 40% of the world’s population.

But for a fledgling social network, Bluesky has created enough of a cultural footprint that it’s bound to stick around. Rome was not built — nor was it toppled — in a day.