Unfortunately, digitally redacted documents aren't the only ones susceptible to attack.
Recently the IRS has come under fire for sending to Tea Party groups probing letters threatening their non-profit status unless they answer a large number of questions.
Fox News redacted parts of the letter, as you can see below.
However, Fox News really failed at their redaction process, and left a lot of sensitive information exposed.
I personally use a photo editor called Zoner Photo Studio, but the same technique can be used in Photoshop.
First, lets play with the image levels a little bit...
Move some sliders around, and text begins to magically appear!
Now let's adjust the contrast and brightness a little.
After performing the manipulations above, I doubled the size of the image for easier examination.
|Click to View Full Size|
Of course this information is already available online anyways, so I'm not sure why it was redacted. However, this could be a very interesting technique to use against Freedom of Information Act documents with redacted sections.
Once again, related reading: A Primer On Electronic Document Security.
Maybe someone will pay attention this time.