The August 2004 article of Law Technology News has an article by Donna Payne and Bruce Lewis on the dangers of Metadata (“Metadata: Are you Protected?” see p.36). The authors make the following statement: “many law firms advise users to publish external documents as PDF files before sending, under the assumption they will be metadata free.”
Yes, law firms do this, but not so much to keep the documents free from metadata, but to keep the documents free of a certain type of metadata. Most law firms who use Word or Word Perfect are aware of the ‘tracked changes’ feature that keeps a record of all changes in a word processing document. Many lawyers wouldn’t want their opponents or adversaries to see those changes, so they wisely convert the documents to PDF files and send those instead.
This is the second time I have seen a warning about PDF files containing metadata, and this is the second time I have concluded that the authors of the warning negligently failed to convey the proper information. The law firm insurer ALAS sent an E-mail to its member law firms earlier this year cautioning people that PDF files contain metadata. And guess what the immediate reaction of most attorneys was?
Most attorneys concluded that ALAS was telling them that if they converted their word processing files to PDF the ‘tracked changes’ could still be uncovered in the resulting PDF file. I’ll bet that many attorneys who read the Payne/Lewis article will think the same thing.
The Payne/Lewis article has a chart to show what sort of metadata is included in PDF files. Here is the complete list: “Authors; Create Data; Filename; PDF Version; Page Count; Encryption Status; Permanent ID; Changing ID; Producer; Creator: Custom Fields; Title; Subject; Keywords: Modification Date; Bookmarks (total #); Annotations (total #, type and type amount); and Page One Size.”
See anything in that list about ‘tracked changes’? No. That’s because the only metadata that is tracked in the PDF is what is generated once the PDF has been created. So, to repeat, if you want to make sure that someone can’t track the changes you made in a word processing document, convert the document to a PDF file and send it to your adversary. If you don’t want your adversary to know all that stuff I just listed above, then consider employment in area that allows you to fully express your desire to be supremely secretive — like, say, the CIA or the Department of Homeland Security.