Jay Graber, the CEO of the microblogging social media site Bluesky, sent a message to Meta CEO Mark Zuckerberg with a T-shirt she wore at South by Southwest.

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

At the South by Southwest conference in Austin, Jay Graber’s choice of attire made a statement about the unchecked power of billionaires. Bluesky CEO Jay Graber took a clear swipe at Meta CEO Mark Zuckerberg when she took the stage at the South by Southwest (SXSW) conference in Austin this week wearing a shirt that copied an infamous one he’d worn last year at a Meta product reveal event.

A Bluesky spokesperson said the network "returns meaningful choice and ownership to each individual user, instead of a single CEO."

Jay Graber’s got jokes. As the Bluesky CEO took the stage for her SXSW keynote on Monday, she wore a black T-shirt with black lettering across the chest, which declared, Mundus sine caesaribus. Or, “a world without Caesars.

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,