I dont think people should make an opinion on something if they know nothing about it .. thats just hypocritical.
The book isnt just about magic, which these people seem to think. The book has many values, morals and a storyline. From the words of Lupin jr, the magic is just a 'shell' which makes it interesting and adds spark and opens up options for the book to explore.
I think banning the books is redtricting the childrens choices and preventing the children from becoming active in something great ... Harry Potter and reading!