Illuminating blacked-out words in redacted (edited/declassified) documents is actually possible with computers today.
Interesting, the government stopped using Courier in its documents recently because it’s ugly compared to Arial or Times New Roman. But, because Courier is a monospace font, it is actually harder to decipher with the method listed in the article. So, the government has made it easier to pierce the veil of secrecy they put around redacted documents. Fantastic.