Just when you’ve started wrapping your head around Bitcoin, a new virtual currency is hitting the headlines.

Millions of Dogecoin, a virtual currency that began as a joke and has seen niche growth online, were stolen on Christmas from virtual wallet site Dogewallet, the firm announced on its website. Hackers stole around $12,000 worth of Dogecoin — since they’re worth around $0.00059 per coin, that amounts to about 21 million coins.

To understand Dogecoin, you need to know a few things: It’s a cryptocurrency similar to Bitcoin — so it’s all digital and traded over the web, or directly from computer to computer — and its name comes from the popular Doge meme, which typically features a surprised Shiba Inu with a hilarious internal monologue.

“The attack originated from the hacker gaining access to our filesystem and modifying the send/receive page to send to a static address,” Dogewallet’s founders wrote on the site. “We’re currently reviewing logs for information. The site is shut down right now.”

The Dogewallet team says it will refund users who lost Dogecoin from the attack, and it also recommends using offline wallets to save coins instead. Dogewallet is mined and traded much in the same way that Bitcoin is — though its origins are far less serious. Whereas Bitcoin is said to be founded by a mysterious hacker, Satoshi Nakamoto (who may in fact be several people), Dogecoin began as a response to a simple meme and has been kept alive by a niche community on Reddit.

This hack, and Dogecoin itself, shows just how fine the line is today between a joke and reality. Dogecoin was initially just a way to satirize the increasing hoopla around Bitcoin, but as more people joined up, it slowly transformed into something pseudo-legitimate. Dogecoin is just one of many virtual currencies currently vying for attention, but it’s certainly the most hilarious.

Another Dogecoin wallet site, Instadoge.net, was reportedly hacked by the same group that attacked Dogewallet. “That makes 30m + 500k. Thanks,” reads a message left by the hacker group #team-ooga, which is assumed to be behind the attack.

Via Buzzfeed