https://wiki.ubuntu.com/Tracker

Comments and Discussion

How to disable tracker globally :

1. Disabling tracker for globally (for all users)
   1. Edit /etc/xdg/autostart/trackerd.desktop file with root priviledges (sudo vim, gksudo gedit ...)
   2. Add "Hidden=true" to the end of the file
   3. Do the same for /etc/xdg/autostart/tracker-applet.desktop if you want
2. Disabling tracker for your user only
   1. Enter the directory "~/.config/autostart", create it if it does not exist
   2. Create a file named trackerd.desktop
   3. Paste the following into the file, save and exit

      [Desktop Entry]
      Encoding=UTF-8
      Name=Tracker
      Hidden=true

- Gokdeniz Karadag