I see a lot of 'white' avatars in the question lists, e.g. here and here. Some user avatars aren't loaded, e.g. https://i.stack.imgur.com/O7K2b.jpg and https://i.stack.imgur.com/gkMl8.png – they just timeout for me. Sometimes (but not always) I do get a nice "Imgur is over capacity!" image, which I'm (rather surprisingly) able to upload to imgur - but you might not see it.