If this image is your work and you do not wish to have it here (Delete), your can contact the site admins and request the removal.
People do not redistribute art on this as an act of rudeness. The site acts as a hub where the user-base may discover new talented artist, as Danbooru strives for providing source links to the respected artists (Pixiv, Twitter, and so on). Danbooru is a great way to gain more followers.
Danbooru also functions as an archive. Many great artists have deleted their online galleries over time and left their admirers sad, being unable to look at pictures they loved. Danbooru enables this lost art to be archived.
Example: Me. I did not know who Tanaka Takayuki was, until today (Discovery!), but I see it is a very talented artist I may want to follow in Twitter to enjoy more beautiful artwork!
