Unfortunately, xkcd (along with NYTimes and probably others) link to CSS/JS resources at http:// http:// URLs, which defeats the security of HTTPS. The next ver

Unfortunately, xkcd (along with NYTimes and probably others) link to CSS/JS resources at http:// http:// URLs, which defeats the security of HTTPS. The next version of Firefox will block mixed content in these cases, and being on the alpha channel, I've had to disable HTTPS Everywhere for these sites.