Quick note: I needed to delete all EXIF data from some photos. After a very basic research, I found an easy and powerful tool: exiv2.
How to install (Linux Mint - Debian package):
sudo apt-get install exiv2
How to delete EXIF data from all JPG files in current directory:
exiv2 rm *.JPG
Again, pretty simple. But quick and effective.
More info at http://www.exiv2.org/