Contact albert if you wish to have an image removed, you will be required to prove you are who you say you are. Considering flagging is anonymous any old troll could flag every image claiming it's their own this is not exactly a contestable matter.

Also, messing up with tags is NOT a right thing to do in such situations. Just contact albert, see "Contact" link at the main page: http://danbooru.donmai.us/

@Fred1515
Regardless of what is written at other websites, we do have our own rules and should comply with them. Qualifiers like _(pixiv) and subsequently _(deviantart) are heavily discouraged. Real name of the artist should be used if it's known. See howto:artist and howto:pixiv.

Given the timing of the message on their Deviantart account, and the tag headaches she's causing, and the fact that there's only one image... We do want to follow the removal request policy as much as possible to avoid trolling, but given that the "don't post on danbooru" message was uploaded to her account after this was posted, it's obviously a very direct connection and clearly not a third party troll.

I've added her to banned artists.