Don't trust PDF documents

I recall when the Nebraska Bar Association told its members to get a copy of Adobe Acrobat so they could produce the PDF documents required for electronic filing in certain courts. I know a bit about how PDF files can hide text and formatting material. This always made me suspicious enough to use software to scrape off as much of this non-displaying stuff as possible from my PDFs. Today Michelle Malkin has a post on how, "bloggers following the Sgrena investigation are linking today to a leaked version of the U.S. military's report on the incident, which appears to inadvertently reveal critical classified information. The link points to an Italian newspaper that gives instruction on how to copy and paste 'hidden' text in the PDF version of the report."

The Italians have been most ungracious in their handling of the unpleasant accident, and all the Bush haters have welcomed their Italian sob-sisters as fellow travellers. If howling Italians give you any concern at all, just get out a pictorial history of WWII and check out what the Italians were up to then. They should keep their traps shut for at least another generation. But the part of the story that caught my eye was the ease with which the anti-American investigators were able to recover redacted portions of a leaked PDF document.

Folk, you have to be careful when working with ANY file format that has hidden formatting code. Not only can these hidden strings of characters be used to hide secret messages, but they can just as easily tattle on the author. Different versions, edits, redactions and subsequent additions are often stored by these complex file types. I wonder how many legal pleadings and briefs contain hidden 'work product' that might be more than just embarrassing.

Should defense attorneys in Federal criminal cases be checking the old electronic filings that sent their clients to the slammer for exculpatory information buried in the prosecution's documents?