We have a feeling that Harry Potter is never going away, in the sense that franchises like Batman and Star Wars never went away (and Star Wars never got its own amusement park). And why not? It's the perfect storm of wonder, charm and innocent, family-friendly adventure that everyone can enjoy.
Which is why we love talking about how pants-crappingly terrifying that whole universe is. For instance ...
6The People in Paintings Are Alive
In the Harry Potter universe, the people in photographs and paintings can move and talk. But it's not like they're just video clips of the person -- hell, we could do that. You actually see characters interacting with the "people" in the pictures, particularly in the portraits that hang all over Hogwarts School -- several major plot points revolve around it. The people in the paintings are able to talk, think and even travel to other paintings. They relay information that no one else has.
"I am innocent but love screaming like a madman."
And as such, some portrait subjects serve as security guards for locked rooms, while others are used as errand boys to deliver urgent messages (they can travel to any room that also has a painting). And, even weirder, these aren't entirely fictional creations dreamed up by some artist, like if somebody made a Mickey Mouse with computerized AI or something -- these are paintings of real people, long-dead former headmasters and such. They possess all of the personality and (presumably) memories of their living selves.
Dumbledore is asleep all the time? Convenient, Rowling. Very convenient.
The Horrific Implications:
Apparently, in the wizard world, if you paint a picture of a dead person, presumably with some magic paint or the right enchantment, their memories and the essence of their personality will be on canvas. Forever. For example, in Harry Potter and the Deathly Hallows, former Slytherin headmaster Phineas Nigellus Black is forced to take orders from his philosophical enemy and student Hermione Granger -- and he is pissed off about it.
Who cares, right? Well, what's stopping that situation from being reversed -- if, after Hermione dies, she gets painted into a portrait and is forced to help some future generation of evil wizard Nazis?
Especially if getting attacked and slashed up is just considered property damage.
That brings us to our second point. Not every magical portrait is going to be of a Dumbledore or a comic-relief character like the Fat Lady at the entrance to Gryffindor Tower. What if some idiot paints a picture of Voldemort? Will it carry all of his evil genius and scheming? Is He-Who-Must-Not-Be-Named and also Has-an-Abortion-for-a-Soul going to be able to help plan the next Event-That-Would-Be-Awful? Somebody in Potterland didn't think this through. The guy has already proven he can carry out most of his plans without the benefit of a body -- Voldemort didn't even have one for the first half of the series.
It's not all that hard to create a magical portrait, after all. In Harry Potter and the Prisoner of Azkaban, Draco shits out a quick sketch of Harry getting hit in the head with a ball and then getting struck by lightning.
One of the crappier animated gifs available.
Maybe this sketch was infused with just enough magic to make it crudely animate, but we already know that more is possible. So what's to stop some Harry Potter enemy from making a painting version of that, just so he has a sentient Potter copy to torture? It'd be a two-dimensional Harry Potter who can think and feel, but who is painted into a situation where he's having angry dicks slapped on his face ... forever.
5Technology Is Frozen Forever
The first difference you notice between the wizard world and ours, other than the presence of wizards, is that their society seems to exist in a time warp.
When Harry discovers he's a wizard, he is whisked away from his big, mean "muggle" family and their modern suburban home into a world replete with bygone wonders from a quaint and magical yesteryear. Gone is the cold and impersonal culture of electronic gizmos and instant-gratification telecommunication; now he will be receiving his mail by "owl post" and writing his papers with quill and parchment. His school is a medieval castle.
"First years go by boat because the cinematic unveiling is more impressive this way."
That's part of the fun, of course. There's enough charm and quaintness to give quaint-and-charming poisoning to some of this world's larger elephants.
The Horrific Implications:
The world isn't kind to people who don't keep up with the times. Film and camera maker Kodak just went bankrupt because they couldn't adapt to a world of digital cameras. The American South crumpled after the Civil War because it wasn't prepared for a slave-free economy. Swarms of charging soldiers were mowed down in World War I because they weren't ready for the machine gun. And we'll stop there, as the examples only get uglier (no reason to start using the word "genocide" in a Harry Potter article, really).
Especially since it's such a gentle children's story.
Now think of the disadvantages wizards have thanks to their adorably backward ways. Like the thing with owls carrying their mail -- it's an obviously slow, impractical and not-secure method of correspondence. What's stopping them from adopting the telephone? You know, in the way that at some point they adopted the use of eyeglasses to correct their vision.
"Arrgh! Laser surgery is such bullshit!"
Non-wizards have had phones for 136 years! Fax machines have existed for more than a century. Yet wizards don't just reject the use of technology -- they're literally unaware that it exists. Arthur Weasley, a wizard who devotes his career to the study of non-wizard technology, is still trying to get his head around "the purpose of the rubber duck."
"A hands-free chess set? Seriously? I have Contra at home."
All of this would be fine if these were just quirky differences, the wizards embracing the old ways at the cost of some inconvenience and the inability to enjoy videos of cats wrestling their shadows. But it's not. What if the next He-Who-Is-Evil-and-Shit gets hold of some muggle weapons of mass destruction? The best wizards couldn't hold his badness back when it was just a magic-on-magic duel -- think about how awful things could have gotten if Voldemort ever found out that muggles are capable of wiping out half a city with non-magic so awful it will deform your descendents for generations to come.
While wizards just have disfiguring furry fantasies.
And no, they won't just use magic to stop it, because they won't know what they're looking at. Wizards are shown not knowing what a cappuccino is; they're not going to understand what they need to do against a suitcase nuke. And don't say that non-magical weapons wouldn't work on wizards -- they have normal, human bodies that sustain injuries just like anybody else's. You could bash a wizard's head in with a rock if she didn't get her rock-stopping spell cast in time. What works with rocks would work better with bullets, or bombs.
"Wait, so you mean a few pounds of this 'napalm' stuff would clear up my Hogwarts problem forever?"
And we're guessing no one, not even Dumbledore, has invented a don't-nuclear-bomb-us spell, much less a keep-cancer-off-our-babies spell. The entire wizard world is a sitting duck, and they can't even warn the higher-ups of the danger without a damned owl.