[wnight]

Of course the user could just videotape the screen and page-down through all of the sensitive data to record it, rendering the exercise pointless.

The first guy was right, it's impossible. Certain very narrow bits of it could be accomplished, but not any real-world goals anyone could have.

[cookiecaper]

Obviously someone interested in copying the data at whatever cost will be able to do it, but that's not the use case pertinent to this story. This would not be designed to taunt your enemies, but rather ensure security of data in the hands of individuals who may not understand how to handle it properly.

The Guardian was operating under a grievous misunderstanding about the nature of the encrypted data, but from my vantage point I don't see that they operated out of intentional malice. If you are distributing data to compliant parties and just want to ensure a tidy cleanup to prevent mishandling or theft, something like this definitely could be useful.