Legal documents are increasingly being filed online, causing some problems as company employees get used to the new formats. Information on paper copies can be redacted with a marker pen, but electronic redaction, if not done properly, can be reversed with a simple cut-and-paste.

Earlier this year, for example, the Associated Press was that showed Facebook's estimate of its own market value. The AP got its scoop by cutting and pasting the blacked-out sections of a court transcript.

The problem is large enough that two months ago the U.S. District Court for the District of New Jersey explaining how to properly redact information.

"Electronically filing PDF'd documents is a relatively new process for lawyers," many of whom have only recently started using desktop computers, said Christina Frangiosa, counsel with the law firm Panitch Schwarze Belisario & Nadel.