Bah! What a waste of a super computer to use it for something like that

Nasa use these powerful computers, another use for them is to factor massive primes that would otherwise render encryption completely unbreakable, hence the constant need to find larger and larger prime numbers - and the move towards quantum computing. Even then, cracking encryption is usually done via distributed computing - I take part in one such project to try and unravel an Enigma coded message from the war (I do some really useful things with my PCs!)

I suppose when you're the FBI trying to outwit terrorists, then you need the best you can get. Not exactly for the home user perhaps