Bluesky’s CEO trolled Mark Zuckerberg at SXSW with a T-shirt. You can now buy it.

UPDATE: Mar. 13, 2025, 3:15 p.m. EDT All sizes of Bluesky’s “A WORLD WITHOUT CAESARS” shirt sold out in less than 30 minutes. We’ve asked the company whether it’s planning a restock and will update this story if/when we hear back. Our original story follows.

The T-shirt heard around the World Wide Web can now be yours.

The social media platform Bluesky has begun selling a version of the shirt worn by its CEO Jay Graber at SXSW in Austin this week. Graber took the stage for a keynote session Monday in an oversized black tee bearing the phrase “Mundus sine caesaribus,” which is Latin for “a world without Caesars.” As Mashable’s Chance Townsend reported, it was a clear dig at Meta CEO Mark Zuckerberg, who infamously wore a similar shirt referencing a Roman ruler at the company’s developer conference last year.

As of Thursday afternoon, Graber’s shirt is now available for purchase for $40 in sizes small through XL at worldwithoutcaesars.com. According to the website, “Any proceeds benefit the AT Protocol developer ecosystem, the open network that Bluesky is built upon.”

Graber’s shirt is a near copy of the one Zuckerberg donned for Meta Connect 2024 — same design, same typeface, but very different message. The Facebook founder’s original shirt read “Aut Zuck aut nihil” (“Zuck or nothing”), a spin on the Latin phrase “Aut Caesar aut nihil” (“Either Caesar or nothing”). Zuckerberg has seemingly spent several years chasing an obsession with the Roman emperor Augustus Caesar.

Mashable has reached out to Meta for comment.

Townsend reported that Graber doubled down on her anti-tech exec messaging in her SXSW keynote, emphasizing the value of open-source, decentralized platforms like Bluesky.

“If a billionaire tried to ruin things, [Bluesky] users could just leave — without losing their identity or data” Graber said.

Bluesky launched in 2023 as an invite-only platform and quickly took off as an alternative to Elon Musk’s X. As of March 2025, it has over 32 million users.