Firefox Lockwise, Mozilla's password manager, will now notify you immediately if you've reused a password revealed in a data breach. Reusing passwords is not a good practice, ideally we'd use strong single logins for all of our accounts, but it's easily done when you're signed in to many websites and services, especially if you've created the accounts before you start using a password. manager to keep track of everyone. Unfortunately, this makes your accounts particularly vulnerable, as a potential attacker can simply try to connect the same details on different sites. Lockwise (which is now built into Firefox as standard, having started life as an add-on) could already warn you if one of your connections was listed after a data breach, so you knew how to change it immediately. , but the latest update goes even further, notifying you immediately if any of your repeating passwords have emerged during a recent breach.