The journalist writing the story has the same level of technical knowledge about how to "redact" properly in the digital realm as the individuals doing the redaction. To the journalist, with zero knowledge of the technical aspects, viewing the "redacted" document, it appears to be "redacted", so when someone "unredacts" it, the action of revealing the otherwise hidden material appears to be "magical" to them (in the vein of the Arthur C Clarke quote of: "Any sufficiently advanced technology is indistinguishable from magic").
To the journalist, it looks like "hackers at work" because the result looks like magic. Therefore their editor attaching "hacks" to the title for additional clickbait as well.
To us technical people, who understand the concept of layers in digital editing, it is no big deal at all (and is not surprising that some percentage of the PDF's have been processed this way).
To the journalist, it looks like "hackers at work" because the result looks like magic. Therefore their editor attaching "hacks" to the title for additional clickbait as well.
To us technical people, who understand the concept of layers in digital editing, it is no big deal at all (and is not surprising that some percentage of the PDF's have been processed this way).