Back in the 1990s, when Tim Berners-Lee and his team were creating the infrastructure of the World Wide Web, they made a list of the error codes that would pop up when something went wrong. You've surely encountered many of them: "404 Not Found," which pops up if you click on a dead link; "401 Unauthorized" when you hit a page that needs a password; and so on. Here's one you probably haven't seen—and its absence from your life speaks to why the promise of the early web seems increasingly out of reach: "402 Payment Required."
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