While it's a convenient feature to have an image from somewhere in the internet be automatically cloned to the (hopefully) permanent i.stack.imgur.com, automatically turning the image into a link to the original (or it's source, which might even be auto-determined for some sites like Wikipedia, maybe even automating correct attribution) would help for correct attribution and further research on that image's source site (instead of having to use e.g. TinEye first). Something like this maybe:
Clarification: The image would still be uploaded to imgur, but in addition its markdown would be a hyperlink to the source (or e.g. its dedicated Wikimedia page).