Zeitgeist is a service which logs user activities and events.

This will purge the activity history, but won’t remove the daemon :

zeitgeist-daemon --quit
killall zeitgeist-daemon
killall zeitgeist-datahub
find ~/.local/share/zeitgeist/ -type f -exec shred {} \;
rm -rf ~/.local/share/zeitgeist/*

You can check the activity history with :

apt install -y zeitgeist-explorer
zeitgeist-explorer
gnome-activity-journal
activity-log-manager

Check also the activity for Tracker with

gsettings set org.freedesktop.Tracker.Miner.Files crawling-interval -2
gsettings set org.freedesktop.Tracker.Miner.Files enable-monitors false
tracker-preferences
# Purge with :
tracker-control -r
tracker-control -S

tracker-preferences is not available on recent Debian and Ubuntu versions.

Install dconf-editor, run it, browse to org > freedesktop > Tracker > Miner > Files

See also :

gsettings list-recursively org.freedesktop.Tracker.Miner.Files

Additional tags : tracker, track, tracking