[bzbarsky]

> Its possible to MITM an HTTPS connection

Not in the case of Firefox connecting to AMO, because it uses a pinned certificate for that.

[click170]

Are you sure?

I perform HTTPS interception on all out-bound traffic on my network and I don't recall making an exception for AMO, and I have a number of add-ons installed. Though, it wouldn't be the first time I've forgotten about something like that.

[bzbarsky]

Did you install your addons before updating to Firefox 32? That's when the pinning was introduced.