Privacy and confidentiality.

Contents hidden in PDF or other files can be easily revealed. Similar is the position in other documents. So are the pictures.

I do feel concerned with this problem. As documents come to us from a variety of unconfirmed sources and we use them as per requirement and also upload and transfer these doc. (See http://www.metadatarisk.org/)

Metadata removal tools for Linux:

Pictures: Shotwell has an option not to transfer meta data. Similar option exist in DarkTable. Phatch also has some features.

Text: Text files are better than doc files which have more metadata, as to who contributed what.

Other Sources:

for Windows, Linux (tarball and deb) and Mac:

http://datacleaner.org/

Windows only:

http://www.superutils.com/products/exifcleaner/

Fedora etc. using yum:

http://hacktux.com/read/remove/exif