Within the TBB, when "Use the Observatory" is selected (not the default) the Observatory preferences look as the attachment shows: Within TBB 4.5: Greyed out: "Check certificates using Tor for anonymity" Checked: "Check certificates even if Tor is not available" This seems inaccurate. Peter points out this may be a relic from when HTTPS Everywhere looked for Tor on 9050. The new Tor SOCKS port within the browser is 9051. This is not causing any leak, however: the wireshark filter "host observatory.eff.org" shows no packets coming through, while the same filter shows packets within Firefox. The TBB may be transparently proxying these certificate reports.