Life imitates art I suppose! You don't see opaque boxes used in Hollywood productions. Blur matches a popular fantasy aesthetic

Opaque boxes have been issues before, when they end up being "semi-transparent" and you can up the brightness to beat them.

Safest is probably just to cut/crop the sensitive bits out.

This is how I get FOIA responses. Agencies just remove the pieces they don't want me to see, sometimes with a code to tell me why it was excised. I use the redaction feature built into Acrobat.

The information is lost if you have a flat image without any layers. You should take additional steps for other formats of course. Granted, it has to be completely opaque of course.

I've used blur in the past. I assumed it was just as secure (please don't hate me!).

I did blur over black box because the blur was less visually obtrusive

Perhaps 'someone' wanted it blurred for exactly the reason they want to de-blur it later....

A certain subset of hackers have had a Gaussian-blur fetish for half a decade now, at least.