When trying to browse https://stackoverflow.com I receive an error that the certificate is not valid. The reason is that *.stackoverflow.com comes with a certificate for *.stackexchange.com at the moment.
More details:
SHA-1 fingerprint of the cert:
DD:BE:B5:C8:5C:F8:40:66:23:AE:1D:93:6B:FE:91:7D:B6:59:CA:54
Issued by: DigiCert High Assurance CA-3