exiftool

Find metadata.

1exiftool image.jpg

Find info on all images in current directory.

1exiftool -ext .png .

You can make this recurring with the -r switch.

And overwrite all metadata:

1exiftool -all= -overwrite_original -ext jpg .

(NB: This does not work on pdf data. See here for erasing all pdf data)

Or just GPS data:

1exiftool -gps:all= *.jpg

You can also use the imagemagick tool:

1identify -verbose