The Problem
After upgrading to Firefox 24, some fonts weren’t displaying correctly in one of my own websites. I was referencing a Google fonts URL in my CSS, because they’re so pretty. And free. And apparently a security risk, according to the new Firefox default settings.
The Fix
Type about:config in the address bar.
Search for “security.mixed_content.block_active_content”, set to false.
For the love of G-d, Firefox devs, please stop trying to protect us from ourselves. It’s ok. We know what we’re doing.