Sites where privacy is a concern use Secure Sockets Layer (SSL) for security. SSL helps prevent a website from leaking sensitive personal or business data, such as a social security number or bank account information, to unapproved third parties. Firefox recommends that you do not turn off SSL certificates, but you may need to disable them temporarily to troubleshoot problems with the browser. You can also delete specific SSL certificates if you no longer need them or you think they're causing an error.