Let's start out with the "usual misinformation" part:
For our readers who do not already know, Harry Potter is the fictional character created by J. K. Rowling for the Harry Potter series of books and films, designed primarily for children. Harry Potter’s story is that of a youth raised in a school for sorcery who learns witchcraft with surprising speed and aptitude.
Now, this is incorrect. I don't recall that Harry is ever referred to as a "warlock", and in the book "witch" is reserved for females. Harry is a "wizard", and the invocation of spirits implied by the use of "witch/warlock" never happens in the books.
It's also not true that he "learns witchcraft with surprising speed and aptitude". One of the issues in the first three books is that he does not learn magic readily, and indeed it isn't until the fourth book that his skills begin to catch up with what others expect of him.
There's thus no real point in bothering with the "witchcraft" angle because it's just not there in the books. (And judging from what has been said thus far about how magic abilities are used, I have to imagine that witchcraft in the sense of invoking spirits would be considered insanely dangerous.) What is worth comment is this passage:
The Harry Potter books are classed not simply as fiction but as fantasy literature. They use detailed imagery to produce an unreal picture in the imagination of the brain. The imagination has such a strong influence over mankind that we are warned by numerous Fathers of the Church to reject the images of dreams and scorn fantasies of the imagination in favor of what the Philokalic Fathers call “pure intellections,” that is, abstract thinking free of images.
The problem is that there is no such thing.
Belief in "pure intellection" is simply a lack of sensitivity to the images that are hidden in every text.
Now, I don't have a copy of the Philokalia handy, but there references I've seen to the citation from St. Hesychios indicate that he is especially talking of a sort of what these days would be called meditation. One could not walk down the street in the mental state he appears to be describing. Nor could one read any text that way-- not even scripture, nor even his own writings. So when the author says:
Because it is precisely through the imagination that the evil one first attacks us in order to lead the soul captive, Orthodox Christians are to avoid as much as possible not only the Potter series but all fantasy literature.
... this is an attack on all fiction of any kind, and practically an attack upon reading itself. Reading comprehension requires imagination.
Regarding so-called “good witchcraft,” be it known that any practice which seeks to manipulate future events according to the wish or whim of the practitioner -- whether his or her intentions are “good” or bad -- is always evil, since it does not account for and even contradicts the Divine Will.
One might as well condemn someone for preferring to wear clothes that fit! The practice of "seek[ing] to manipulate future events according to the wish or whim of the practitioner" is called planning. Is planning evil? I think not!
Harry Potter, therefore, is not appropriate for anyone to read. The books are intended as an initiation into the world of witchcraft.
And here we go. Never mind that nothing has been said to defend such a claim-- the problem is that the author is now using the very tools he has denied himself. Reading these words, you are supposed to conjure up a fantasy of Ms. Rowling as planning out a series of books intended to make the occult enticing. And as for the next passage:
For anyone who doubts or denies this, let him visit a Barnes and Nobles or Borders bookstore and observe which books accompany Harry Potter on display: the series is surrounded by books about witchcraft aimed especially at teenage girls, and it is rarely, if ever, prominently displayed among other children’s books.
... this is, in my experience, utterly untrue-- and anyway, Ms. Rowling doesn't have that much control over this.
I just went to Borders the other day. HP was, of course, standing by itself in the front, and also had some shelf space in the kids' section. Occultish books? Over in a different section, next to the case of tarot decks. Oh, and the Scholastic book fair. Occultish books? You have to be kidding!!! The set up shop in the public schools; the cultural conservatives would take them apart for doing something so stupid!
But besides, there's that image again: a picture of Harry Potter next to the Pictorial Key to the Tarot. It's a pleasing fantasy for some, but it is still a fantasy.
As usual, there's no addressing here of the moral points taught in the HP books. And it's hardly surprising, because this teaching is utterly conventional, conservative, and essentially Christian.