According to many earlier sources bitcoin must already be dead. They are sure it will not even last a year. In reality the my guess as to the3  biggest threats would be:

1. SHA encryption is broken. Bitcoin would be the least of our problems then.
2. A concerted, sustained international effort by governments to make bitcoin illegal.
3. A collapse of the Internet infrastructure. No network, no bitcoin.

As far as aliens or secret societies... Get back in your Mom's basement weirdo.