I'm totally cool with taking stuff down if the artist who did it wants it to be taken down (which has already been happening to some extent) but I think that the two principles of e621 that I don't want to lose are:

• Anything posted to a freely accessible site like FA is fair game to post until the artist explicitly says they don't want it to be on e621.
• Anything containing a licensed character that the artist doesn't own is fair game, no matter what, and will not be taken down.

I know getting on the artist's good side is nice but I think (as an artist myself) that these principles are universal and should be understood whether you like them or not.