This won't stop people who disrespect the license or personally insult the developers [indeed, it's bound to cause a whole lot if it! I hope we can do better in this thread], but it will have a negative effect on contributions. I wish the developers well, and don't have a _different_ constructive action to suggest (legally pursuing infringers is a slow, expensive, and uncertain game), but I am not optimistic that this is a good choice or good for the long-term health of the project.