It's amazing that the government is still making these mistakes (assuming it's not deliberate).

This kind of error is as old as PDFs. The text is there, it's just covered with a black blob.

Policy at CIA, NSA, etc. was to NEVER use PDF or electronic features for redacting text. While it can be done correctly, it's easy to mess up. Physical masking or physical removal (better) of the redacted text, then rescanning documents into fresh electronic format. I would think with today's technology, even physical masking is defeatable in many situations.