Bug 1529934 - Extension block request: {5997e7bd-1940-4058-a5f4-1562afce6353}
https://bugzilla.mozilla.org/show_bug.cgi?id=1529934

これはダメでしょ
Undo Closed Tabs Button
Fake Firefox update page, remote ad script injection on every page, including replacing Google Search results with ads