Hermione had gone through every rule regarding Muggles and using magic against them. Any spells cast against them, or in their sight would have her in front of the Wizenagmot in seconds. But polyjuicing as them was not illegal. It might not be ethical the way she was doing it, but it wasn’t illegal. Neither was using certain potions on them. The laws had been amended years ago. The spirit behind the laws was that Muggleborns could use healing or calming draughts on their family members who already knew about magic. But the letter of the law was clear, "any non-harmful potion can be administered to a Muggle’. So, with all the laws in mind, Hermione had begun to seek revenge. 