Columbia Journalism Review: “Hyperlinks are a powerful tool for journalists and their readers. Diving deep into the context of an article is just a click away. But hyperlinks are a double-edged sword; for all of the internet’s boundlessness, what’s found on the Web can also be modified, moved, or entirely vanished. The fragility of the Webposes an issue for any area of work or interest that is reliant on written records. Loss of reference material, negative SEO impacts, and malicious hijacking of valuable outlinks are among the adverse effects of a broken URL. More fundamentally, it leaves articles from decades past as shells of their former selves, cut off from their original sourcing and context. And the problem goes beyond journalism. In a 2014 study, for example, researchers (including some on this team) found that nearly half of all hyperlinks in Supreme Court opinions led to content that had either changed since its original publication or disappeared from the internet. Hosts control URLs. When they delete a URL’s content, intentionally or not, readers find an unreachable website. This often irreversible decay of Web content is commonly known as linkrot. It is similar to the related problem of content drift, or the typically unannounced changes––retractions, additions, replacement––to the content at a particular URL.