The Mozilla team announced the new version of SmartBlock with the launch of Firefox 90. SmartBlock is Firefox‘s tracker blocking mechanism built into Firefox Private Browsing and Strict Mode. It combines a web browsing experience with privacy protection by ensuring that the user can still use third-party Facebook login buttons to sign in to websites.
Firefox Private Browsing blocks Facebook scripts by default because its partner Disconnect includes Facebook on the list of known trackers, which caused Facebook logins to no longer work. By clicking on the Enhanced Tracking Protection shield in the address bar and click on Tracking Content users will notice that the browser has blocked third-party tracking content from Facebook to prevent any possible tracking.
SmartBlock 2.0 eliminates this login problem. If the user clicks on the “Continue with Facebook” button SmartBlock reacts by quickly unblocking the Facebook login script just in time for the sign-in. SmartBlock 2.0 provides this capability on various websites. If the user hasn’t signed in, Firefox continues to block scripts from Facebook.