As Terra Luna’s death spiral accelerated, its supporters, known as “Lunatics,” lurched between terror and hope as Mr. Kwon shoveled more than $1 billion in Bitcoin into the system in an attempt to restore stability. “Deploying more capital — steady lads,” he tweeted.

But ultimately, there wasn’t enough cash coming in to make up for outflow, just as in an ordinary bank run, and this particular experiment in replacing trust with mathematics was at an end. Among the many thousands of failed crypto experiments, Terra Luna stands out as one of the largest, taking with it roughly $60 billion in total market value.

The vociferous opponents of crypto have been quick to celebrate the death of the blockchain, insisting that all crypto is fraudulent. These critics are a mirror image of the equally unrealistic cheerleaders at the opposite end of the spectrum: the pro-crypto libertarians clamoring for a financial world with no regulations whatsoever.

Responsible players in the crypto market have been calling for and helping to develop sensible regulatory frameworks for many years. A bedrock of crypto regulations already exists; in the United States, federal agencies such as the Financial Crimes Enforcement Network, the Securities and Exchange Commission and the Commodity Futures Trading Commission started weighing in on separate aspects of trade and taxation in 2013. In October, the Department of Justice announced the formation of the National Cryptocurrency Enforcement Team. The list of crypto scammers who have gone to jail already far surpasses the number of bankers jailed in the United States for their role in the 2008 financial crisis.

In the early days of the internet, the circus atmosphere made it easy to ignore the dangers that were brewing — surveillance capitalism and illegal government snooping among them — and that would have grave global consequences. In time, regulations were put in place: privacy frameworks, like some provisions of the 1999 Gramm-Leach-Bliley Act in the United States and the 2016 General Data Protection Regulation in Europe, and speech protections like Section 230 of the Communications Decency Act.

At the same time, the marvels of the internet multiplied, magic that by now seems unremarkable: a map of the world, street by street, in your pocket; instant translations from almost any language; a look-up service for every branch of knowledge; global, near-instantaneous news. Today’s internet is deeply woven into the world’s economies, media, politics, industry and social life, in good ways and bad.