Firefox automatically alerts users when you access sites that have data breaches

Mozilla recently announced that the Firefox Quantum browser had added a new security feature that automatically displays warnings from Firefox Monitor when users visit sites that previously had data breaches. This feature is designed to alert users to possible problems and advise them to check their emails to see if they have been compromised.
When an alert occurs, the user can click the Check Firefox Monitor button to go to the Firefox Monitor site or click the Dismiss button to turn off the alert or click the down arrow to select “never show Firefox Monitor alerts” to disable this feature. According to Mozilla, this alert feature is not intrusive, with only one occurrence per site, and just for sites that have experienced data breaches in the past 12 months.
Firefox Monitor is a free privacy data disclosure notification service. To use it, visit the Firefox Monitor website and submit an email address. It compares with the more extensive database of more than 3.1 billion identified security issues in “Have I Been Pwned” and promptly alerts users when problems are discovered.