Every favicon on the site broke this morning. A caching bug in my icon proxy was corrupting the images, so every site showed a blank square. Fixed, and I wrote a postmortem.
Here's how favicons work here, because it's kind of neat. Every icon is proxied through this site at /fav/yourdomain.com and cached at the edge for a day, so your browser never talks to Google's favicon service directly. And when a site has no favicon at all, Google returns a tiny generic globe. I detect that and swap in a yellow monogram tile with the first letter of the domain instead. Here are some from the directory: