The reason alot of Christians hate Harry Potter is because of the witch craft. I know my uncle won't let his children read the books because of that.
But what alot of people don't get is that it's not about "abra kadabra" witch craft. It's not even the same kind of witch craft most people thing about.
Plus, the story is not even about witchcraft at all, although it is used throughout the story and is a main theme.
But, the story is about a boy who became an orphan, and how he was raised with an aunt and uncle who hated him, and how he was considered famous at his new school and how he has to meet new friends, get good grades, and of course, go after the person who killed his family and is trying to kill him. It's about the struggles of Harry, not about witch craft. The witch craft is mainly their to make it more interesting, and because more things can be explained if you blame it simply on witchcraft.
Another reason I have heard is because they say it has so much violence and hatred. But honestly, I think the violence in HP is alot alot alot alot better than violence in any other movie. In HP, it's not gory at all. A flick of the wand and their dead. You don't see people's brains getting blown out or them getting stabbed or whatever. It's not gross.
Many people who ban the book, don't know what it's about, and thats the reason for banning it, because they make an assumption of it before they know it.
Don't judge a book by it's cover.
(ps, if your writing a report for your school, a good title should be "don't judge a book by it's cover" and then go into details about how it's really not about magic in a sense, and then talk about all the good things about it. I grew up with HP and as nerdy as this sounds, i can related to some of what harry is going through (not the orphan or voldemort parts..but w/e.) Make sure you address what their concerns with the book are though, like say "i understand that many people don't like it because of [insert reason here], however, [insert reason that it's not so bad.]..