Still Working on the Earth-Shattering Kaboom

Well-meaning scientists have managed to drill a hole in the middle of the Atlantic Ocean that goes all the way to the bottom of the Earth's crust. Not content to rest on their laurels, they now want to keep drilling 'til they break through to the mantle.

Yes. The mantle. The hot liquid molten part. The "stuff that comes out of volcanoes" part. After all, it's not like we have enough volcanoes without them going and drilling a new one. What could possibly go wrong, anyway? Releasing stuff from the Earth's mantle... hmm... so maybe there's a wee tiny risk of it erupting violently, triggering tsunamis that go wipe out the East Coast and all that... ;)

But yeah, it probably won't happen like that.