Why Do We Love Zombies?

Zombies are EVERYWHERE!! Wait, don't panic- we mean in pop culture, not outside your window. But why is that? Bad guys and monsters seem to go through phases: one decade there's a dozen movies about aliens, ten years later it's vampires. And right now, it's zombies. There must be something that makes us fixate on one antagonist trope. So what are we afraid of now? It might just be technology.