Remotely Hosted Avatars for 3.5?

[Justice]

Well, the majority will be large, animated gifs. That's why I don't want them uploaded to the forum.

And the file size and dimensions will be checked when they submit the first time. If they change it later to something inappropriate, they can be warned, edit it, etc. The same as if they posted an image and changed it later. That's no reason to not allow hotlinking images in posts.