Being a website which prefers to document from an objective point of view, while offering sources on our information, we of course promote the correct sources being added to the media uploaded to our website. We give credit where its due, and promote our users to do the same.
That being said though, I hope you can understand how the sources tend to get hard to find on this large web, and we can’t always be certain that the place we found the image is by the actual creator. That’s why I like it when artists add their nick or autograph below an image, it allows them to be credited even when we fail on our part (image sharing hosts watermarks don’t fall within this, because fuck those).
There are of course some exceptions to this case, like art or photoshops which were first posted on 4chan. It’s next to impossible to properly source them, as in a lot of times the source isn’t anyone. It also occurs at times that Tumblr blogs change their nick or delete their account, which makes the source link generate an error.
But we’ve improved on our end as well, and offered options to make the adding of sources simpler. For example all our image pages offer a Claim Authorship button, which offers the creators or those familiar with them to claim authorship on the upload and have them edited in the notes. Recently we also introduced public tagging/sourcing to the userbase, which allows users with a certain milestone of image uploads to edit image pages as to add tags and sources. So even when either we or the uploader fails to find the source, someone viewing the image might not.