User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; fi; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3 (.NET CLR 3.5.30729) Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; fi; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3 (.NET CLR 3.5.30729) As a security measure against CA's handing out certificates for sites, firefox should detect changed issuer for a site, and provide a warning about this. This would make it harder, for example, goverment CA's to provide MtM certificates for filtering/screening purposes. Reproducible: Always Steps to Reproduce: 1. Create a site with SSL certificate signed with trusted CA 2. Change the ceritificate to another signed by another CA 3. You will still be told that the site is secure