Confused photocopiers randomly rewriting scanned documents
Photocopiers exist to produce close enough replicas of original documents. Traditionally, they just spit out the result onto paper. Most copiers these days can operate as (generally rather large) scanners, generating PDFs, TIFFs, or other electronic representations. But some Xerox copiers have recently been found to produce scans that, well, aren’t that close to the originals at all. The copiers are producing documents that look superficially similar to the originals but switch around numbers apparently at random.