With the latest HTTPS Everywhere (5.0.5). To reproduce: mkdir /tmp/obstest && \ firefox \ --new-instance --profile /tmp/obstest Install HTTPS Everywhere, and turn on reporting to the observatory. Allow the browser to restart, and visit https://www.jottit.com/ Now, we've reported the certificate once to the observatory. Time to close the browser and see if it reports the certificate again: firefox --new-instance --profile /tmp/obstest --jsconsole Navigate again to https://www.jottit.com/ - see how the console shows another certificate report. I get this in the console: POST XHR https://observatory.eff.org/submit_cert#0.080083105198849420.4907663682697673 [HTTP/1.1 200 OK 306ms]