I use OpenID to log in to all my Stack Exchange accounts. If my OpenID provider ever shuts down, will my profiles be inaccessible? Will I have to register new accounts, thus losing all my reputation, badges and favorites?
Relevant help center pages:
If you cannot log into your OpenID provider, or if you know your provider has ceased supporting an OpenID, please create a new account and then contact us to request an account merge.
Still, it's better to prevent problems if you know this will happen, so…
Please Note: MyOpenID is no longer actively supported by Janrain. If your only login for your Stack Exchange account is MyOpenID, we suggest that you add a backup login method, as any outages in MyOpenID could lock you out of your Stack Exchange account.
Adding additional logins to your account is useful because it provides a way to access your account in case you lose your password. You can choose Google, Facebook, Yahoo!, and other popular OpenID providers; create a new Stack Exchange OpenID by providing your email address and creating a password; or you can manually enter another OpenID address.
Note that account recovery does not work with external OpenID providers.