[bfdm]

A service provider could check the API for the signup email and if previously compromised could challenge the signup with additional CAPTCHA steps to detect bot activity. They could check email+PW entered against leaked pairs and prevent you from registering with a known-compromised PW.

Your bank could check emails attached to customer accounts and work with affected customers to ensure their bank account access is secure.

You employer could check for leaks of accounts using corporate domains. They could check leaked passwords against known last 5 to see if there are active threats.