The Google Analytics scripts runs on a page that appears to be a system/UI page in Firefox, when you search for new add-ons. The response from Mozilla about Pi

The Google Analytics scripts runs on a page that appears to be a system/UI page in Firefox, when you search for new add-ons. The response from Mozilla about Piwik being too much work is concerning. The optional NoScript add-on does stop this script from running, even on that page. You'd have to configure NoScript to block Google Analytics. I, for one, globally block Google Analytics scripts. Incidentally, I also block third-party-site Google.com scripts, but that is harder on websites like Hacker News, which will sometimes send for a Captcha check that only completes successfully with Google.com enabled in NoScript. [edit: I am using the legacy add-on, which Mozilla I guess will disable in November 2017]