DATAMINING AND THROTTLING. The extension worked at first, but they have a customized option in the extension's management section that gives the app full unilateral excess to your total web history, typing and any credit cards you submit while this extension is installed. An App that only works on Youtube should not have access to what Credit Cards or purchases I've made on Amazon. This is set to "default" upon install, and the Extension does not notify you of access to ALL websites. Already reported to Firefox for violations. Also throttles what quality you can download (falsely claims as errors when trying to download above 480p, but only AFTER you deny it's spammy (on screen) requests to give them money and "upgrade" the extension. So yeah, overall it data-mines you without your knowledge and the extension deliberately throttles your download ability after rejecting to upgrade. The "don't show notifications" option also does not work, because again, this Firefox extension is designed to delete your preferences only after 7 days so it can continue to send you spammy requests to "upgrade".