Disable Zeitgeist in Ubuntu 16, 17

Zeitgeist is a service which logs the user's activities and events (files
opened, websites visited, conversations hold with other people, etc.) and
makes the information available to other applications.

Below are the steps to disable it and remove the history.

You probably have seen many advices on the Internet that tell you to remove
the zeitgeist packages completely, however doing so will cause the core gnome
packages erased as well.

In fact, you do not have to remove everything. All you need is to mask
zeitgeist services. But before, it might be also a good idea to clear
Usage Data for all time and stop recording it.
To do this, start the "Security & Privacy"

unity-control-center activity-log-manager

Go to All Settings -> Security & Privacy -> Files & Applications
untick Record file and application usage

Securely remove the data under ~/.local/share/zeitgeist

$ find ~/.local/share/zeitgeist/ -type f -exec shred -uvz '{}' \;

Now you can disable Zeitgeist services

$ systemctl --user list-unit-files |grep -i zeitgeist
zeitgeist-fts.service                   static  
zeitgeist.service                       static  

$ for i in zeitgeist-fts zeitgeist; do
  systemctl --user disable $i
  systemctl --user stop $i
  systemctl --user mask $i
done

$ sudo apt-get purge zeitgeist-datahub
$ zeitgeist-daemon --quit