Can non-logged in users upload images?

Hi!

We're trying to use the wiki as a way for people to add their own images to articles. However, when I create a wiki page, and then edit it as a user not logged in, it doesn't seem like I can upload images to the text. It might be a way to refer to an external image via an url, but this is too much hassle for our users.

Is there a way to fix this?

An upload image icon in the toolbar in the edit text section (available for anyone) would be great!

Regards,
Ben