Griefing

Please help, some player keeps repainting parts of my drawing back to green, and when he runs out of pixels, he switches to a new account. Because of him, I can't draw other art, because all the pixels go to recovery. Please block him by IP or something like that. If I stop restoring pixels, my art will turn into a green zone. 

https://preview.redd.it/xagknxsetrmf1.png?width=2007&format=png&auto=webp&s=1aed6f1f858960b39be6046cf74dc64fd3faa5e4