Surely, they know something that rest of the world isn't familiar with!
Personaly, I think it has something to do with the prophecy of Mayas...all that stuff about end of the world! Considering everything what's going on in the world nowadays, I think it will be either some nuclear or natural catastrophy!
This may be a little apocaliptic thinking, but all of these natural catastrophies all around the globe in last couple of years, made me think this way...don't let this scare you, it's just my homble opinion :-)