The fact that this site doesn't serve HTTPS(correctly) remains a head-scratcher for me.
The certificate isn't valid for paulgraham.com, hence the error. It is valid for *.store.turbify.com, among other SANs, which seems to indicate that the site is hosted by Yahoo[0] and has HTTPS misconfigured.
Yeah it's weird: I've got my Firefox configured to never load HTTP sites but I'm too sure why it then tries to load the HTTPS one when a HTTP URL is given.
Anybody else got some similar error?