The Dark Knight effect

So Lizzy tells us this morning, very matter-of-factly, as we pull into the day care that also serves as her before-and-after school care, that a girl (her age, as it turns out) told her yesterday that if she didn't get up from the chair Lizzy had just sat down in, she was going to "stab her in the eye with a pencil." Hmmmm. A familiar scene, for anyone who has seen summer's charming blockbuster.
We asked what happened next, etc., etc., and Lizzy says she ignored the girl, who kept bugging her, so she told a teacher about it, who told Lizzy to "tell the girl to chill out." Lovely proactive intervention on his part. And it sounds like the girl didn't chill out. Lizzy says she eventually moved off to somewhere else to avoid the girl.
It's hard to know what actually happened in these instances -- was Lizzy more at fault than she told us, or even than she realized? -- but regardless, Matt and I were pretty horrified by the ghastly quality of the girl's threat. It's one thing to threaten someone; it's quite another to do so in such a graphic manner.
There's a reason we don't watch PG-13 movies with our kid, especially ones that should have been rated R in the first place. If only more parents followed suit. Granted, that's quite judgmental of me. But ... gimme a break with this. Perhaps at least have a conversation with your kid about how a deranged, amoral killer is not a good role model?