Firefox is testing out a warning system that will notify users when they visit breached sites and offer the option to be notified if a site they previously visited becomes breached in the future.
The “Breach Alerts” will not prevent a user from visiting a site but will give them some sort of idea that the sites security features are less than optimal using data provided by Have I Been Pwned?.
“Firefox is just looking at which sites have been breached and we're discussing other ways of using the data in the future,” Have I Been Pwned founder and independent researcher Troy Hunt told Engadget. “They've got a broad reach and surfacing this info via Firefox is a great way to get more exposure around data breaches.”
Nihanth Subramanya, a developer with Mozilla, wrote on his GitHub repository that the extension is going to be used as a vehicle for prototyping basic UI and interaction flow for upcoming Firefox Features. The extension also features an input field which allows users to subscribe their email addresses in order to receive alerts if a site they previously visited is affected in future breaches.
Subramanya admitted the future notifications feature may raise some privacy concerns as it requires users to submit their emails to receive notifications.