Machines that manipulate qubits, quantum computer, can do things that are impossible for a classical computer. Quantum computers are, theoretically, more powerful than classical computers could ever possibly be. Build a sufficiently large one and you can crack all the ciphers on the Internet; as a little game, you could listen in to any "secure" online transaction, crack the code and steal the credit-card numbers and personnal information that have been exchanged—something that is beyond the ken of the best supercomputers in the world.

Charles Seife, "Decoding the universe", Chapter 7


Yes, but can it tell whether this boy is cute or not?