I prefer to remove Exif data before uploading images to the web. My main reason is that I dislike the idea of the whole internets getting lat/lon coordinates of where the photo was taken.
jhead is my command-line tool of choice for removing Exif data. It is a powerful tool that can do a lot more than remove Exif data, be sure to check out its man page or the on-line docs for detail. The
-autorot feature comes recommended.
Install jhead (instructions for Debian-based Linux flavours like Debian, Ubuntu, Mint or so) :
sudo apt-get install jhead
Remove the Exif data from a specific JPG file:
jhead -purejpg /full/path/if/you/want/filename.jpg
Or on a bunch of jpg files:
jhead -purejpg *.jpg or
jhead -purejpg *.JPG