All credits go to Das_Mervin's sporking of the Twilight series: link

I just wanted to cut out this snippet and paste it here because I completely agree here. There is no being that's invincible, no matter how unnecessarily overpowered you make them.
Meyer thinks that humans are limited to two types of weapons: guns and slow-moving bombs. Oh, Meyer. You silly, silly bitch. There is one thing that we humans have been consistently good at since we first picked up a rock and looked speculatively at that turtle hiding smugly inside of its shell:

We’re really, really good at figuring out how to kill things.

But we don’t like to stop at “kill it dead”. Nah, that’d be boring. We like to figure out inventive ways to kill things. And we like to do it with pizzazz. We like to figure out how we can kill as many things as possible with just one tiny weapon. We like to think up many different kinds of weapons to do the job for us. We also like to see if we can kill just that one thing that’s hiding and leave everything else around it untouched. We can target literally anything we want. All we need to do is exploit a distinctive trait that whatever we want dead has. We can kill multiples, we can kill singles, and we can do it creatively.

And it is the twenty-first century. We are armed with a lot more than just sticks and, what did you call them in Bree Tanner…ah yes, “pop-guns”.

A whole lot more. (link)

Think of the sheer amount of military-grade weaponry you know about from the USA alone. Now think about all of the military-grade weaponry you know about from other countries. And now think about all of the military-grade weaponry you probably don’t know about because it’s kept top secret.

Your vampires have basically just revealed themselves to humanity. We know they would—look no further than Bree’s own words about her species to get confirmation of that:

"Again, I imagined the whole horde of us on the loose without a curfew. I could see Diego and me moving like ninjas through the shade. But I could also see Raoul, Kevin, and the rest, sparkling disco-ball monsters in the center of a busy downtown street, the bodies piling up, the screaming, the helicopters whirring, the soft, helpless cops with their dinky little bullets that wouldn’t make a dent, the cameras, the panic that would spread so fast as the pictures bounced swiftly around the globe.

Vampires wouldn’t be a secret for very long. Even Raoul couldn’t kill people fast enough to keep the story from spreading."

Yeah. Without fear of repercussions, vampires would gladly march out into the sun and start killing people for no other reason than to laugh and show everyone how powerful they are and crush the humans beneath them because they’re gods and humans are tasty morsels.

You have just introduced a global threat to the human race. This isn’t something that is attacking one country—oh no, these things are attacking everybody. This is the equivalent of an alien invasion.

*delicately* You just united seven billion people against a common enemy, and those seven billion people have more technology, weapons, and ways to kill you than you can possibly comprehend.

You can’t hide—we can easily find you. You can’t blend in—Meyer didn’t make you that way. You can’t run—your top speed is 180 mph. You can’t hide behind human shields—we can narrow the focus and kill just you. And most of all, you do not have the advantage. Meyer’s all about numbers, as we know, and brute force. It is now, at most, a few thousand vampires against SEVEN FUCKING BILLION.



I know you think you’ve made your vampires invincible against humans, Meyer, but the truth is you haven’t. Aro is right—humans would wipe them out. We would. We would kill them all, your precious Cullens included. And if you continue to insist that no mere human weaponry could kill them, well, you also provided humans with two potential allies that are very powerful and can definitely kill your vampires, because they have.

Shape-shifters and werewolves. Shape-shifters are guardians against vampires, and werewolves were driven to the brink of extinction by vampires.

The only possible way the Cullens could survive a human uprising would be to side with the humans and reveal all vampire weaknesses and fight with them. Even then, they would so not get to go back to their lifestyle once it was over. They would have severe regulations and restrictions placed upon them—if they weren’t just locked up in a lab on Area 51 for the rest of eternity—to say nothing of what the government and law officials would say when they discovered all of the ill-gotten gains the Cullens have been sitting on for the past few centuries. All of that money would go bye-bye.

Basically, Meyer, what I’m trying to say is that you have made yourself a world where they Volturi have to exist for your Cullens to enjoy your perfect fantasy life. The Volturi are guaranteeing the Cullens’ lavish, untouched existence. They don’t have to worry about the Southern vampires coming up and trying to take them out and take their territories, they don’t have to worry about vampire babies eating all their food or destroying their stuff, they don’t have to worry about werewolves killing them, and they don’t have to worry about humans tracking them via their heat-sink bodies or a slight glimmer from their sparkly cells and firebombing the shit out of them. They get to live without fear of anybody killing them and get to enjoy all of that money and rich stuff because the Volturi keep vampires in check and make sure they don’t run wild and destroy the world—because you said it yourself. Without the Volturi, they would.

You fail on every conceivable level.