So far, I've only seen one site where blocking scripts from Google Analytics broke a feature of the site, so I think it's pretty safe. You can use the YesScript extension to block scripts from individual sites. See: https://addons.mozilla.org/firefox/addon/yesscript/ As a more general purpose solution to reducing the burden of tracking scripts, but with more potential to break site functionality, you could take a look at these: * Blur: https://addons.mozilla.org/firefox/addon/donottrackplus/ * Disconnect: https://addons.mozilla.org/firefox/addon/disconnect/ * Ghostery: https://addons.mozilla.org/firefox/addon/ghostery/