Password Monitor is now available in Microsoft Edge preview builds

martmcd well, the monitor would notify you of that , plus the passwords would be hashed and salted to make it more tricky, if they stored your password.

If they don't store passwords, then they'll need to have the username and url to actually make it work as you cannot overwrite usernames in all sites as that would be a security issue. If that was the case on a webpage, the developers might as well allow code-injections like DROPTABLE because you could then just overwrite it and the account data would be gone for everyone.

The process could also be done locally (on the computer) too instead of the server although it would be, depending on your computer, slower.