Firefox 74 comes with an enhanced Facebook Container Extension that lets users add custom sites so they can login with Facebook wherever they need
Prompt to install enhanced extension is the first thing you'll see — The first thing users will see after updating to Mozilla's latest browser … Tweets: @rockymountviews , @chaz_6 , and @linuz90 Tweets: @rockymountviews : So, I launch Firefox and it runs an update. This is on the Update Web Page. Um, no Firefox, it is not okay to like Facebook. https://twitter.com/... @chaz_6 : The new #firefox 74 doesn't bother to check if you already have the facebook container extension installed... sloppy Fabrizio Rinaldi / @linuz90 : I love how Facebook is being treated by modern browser as a proper virus. This is Firefox 74 https://www.mozilla.org/... https://twitter.com/...
Context & Ripple Effects
Mozilla's Facebook Container Extension launched in 2018 as a hard wall: it isolated Facebook's tracking pixels from the rest of a user's browsing by fencing the social network into its own tab container. Firefox 74 turns that wall into a configurable tool — users can now add custom sites where they still want to log in with Facebook, and the update flow puts an install prompt front and center.
First-order effects
- Users who rely on 'Log in with Facebook' no longer have to choose between that convenience and container isolation — custom-site support makes the extension usable on the sites that actually demand Facebook auth.
- The aggressive post-update install prompt drew immediate user pushback on social media, including complaints that Firefox 74 doesn't check whether the extension is already installed before prompting.
Second-order effects
- Sites using Facebook login regain compatibility without asking users to uninstall their protection, removing the main reason people abandoned the container — and Mozilla followed this softening with harder measures like stripping Meta, HubSpot, and Marketo trackers from URLs in later releases.
Third-order effects
- If the pattern holds, browser vendors keep absorbing privacy controls that once lived in third-party extensions — Mozilla's arc from 2018's isolation experiment through native tracker-stripping points toward the browser itself becoming the enforcement layer between users and platforms like Facebook.
The trend: Browser makers are moving privacy enforcement from optional add-ons into core product defaults, with Mozilla iterating its Facebook containment from strict isolation toward managed exceptions.