u/BuddyAlarmed4826

My art on tumblr is currently getting stolen and reuploaded on Pintrest. I only use the site for references so I was shocked when I saw my art.

When I click on the posts it doesn't link me to someone creating the pin but to the hashtag on tumblr. I don't want my art circulating on Pintrest with the method. Is there any way I could take down the posts or have my future art not being reuploaded? I don't really want to go straight into copyright claim.

Tldr; How do I unlink a tumblr hashtag I used for my art to stop it being reuploaded on pintrest?