https://www.cnet.com/news/firefox-monitor-warns-if-website-youre-visiting-suffered-data-breach/

"While using the Firefox Quantum browser, when you land on a site that's been breached, you'll get a notification. You can click on the alert to visit Firefox Monitor and scan your email to see whether or not you were involved in that data breach," said Nick Nguyen, Mozilla's vice president of Firefox, said in a blog post announcing the development Wednesday.

The service shows that, although data breaches are distressingly common as attackers become more sophisticated, the tools we have to respond to them also are getting better.