Recently, Stack Exchange regenerated users' identicons for security purposes, which you can read about here. It happened a few days ago, and it seems that a bunch of users on our site now have the same profile picture. There are two sets. This image is the profile picture for this, this, this, th...

Note: When identicons were regenerated network-wide, all the "default" identicons were replaced. However, I'm still wondering if there's an explanation for why this originally happened. Why do so many users have an identicon without a hash value (i.e. use the default identicon)? I realized at so...