Desinstalación completa de Dropbox en linux

dropbox stop
dropbox status # Should report "not running"
rm -rf ~/.dropbox-dist
rm -rf /var/lib/dropbox
rm -rf ~/.dropbox*
sudo apt-get remove nautilus-dropbox
sudo apt-get remove dropbox
rm /etc/apt/source.d/dropbox

Si quieres eliminar el contenido de la carpeta Dropbox:

rm -rv ~/Dropbox