A similar method was used to uncover the name of a game mode in a teaser video from nintendo. Since it was a video the pixels would change as things moved and you could reverse the pixelation fairly well.
Cannot find source.
> Two French hackers used their computer skills to reconstruct a blurred-out code on TV and claim bitcoins worth $1,000 (£760).
I think the hackers could have made more money if they got real jobs doing valuable work.
These kinds of mistakes show up constantly. Another one that often works is when people draw black bars over words they are often no 100% opaque and you can chuck them in to gimp, drag the levels around until the original word is exposed.