Unfortunately it's not photographs I seek to host. Despite their name, Photobucket don't appear to have any such restrictions.
Quoth Flickr's community guidelines: Don’t use your account to host web graphics, like logos and banners. If we find you using your account to host graphic elements of web page designs, logos, icons, and other non-photographic elements on other web sites, we will warn you or delete your account.
I want somewhere to put forum avatars and images used in forum posts. For example, here [link] is an image I used to demonstrate the various sizes of objects in a game. Why I would want a gallery containing such images to be private is just a matter of preference for all it truly matters; the main stipulation is that I be able to access them via an account and thus be able to manage them (edit, delete, whatever).