Bicycle - Impossible Search

The magician, shows a deck of cards both front and back, has one or more cards selected, and puts them back in the deck. This is then squared, and thrown into a paper bag. The bag is shaken vigorously, so that there I no doubt that the cards are randomly mixed up inside it. He then puts his hand inside the bag, and in an instant incredibly finds all the cards chosen! 

It's a real miracle!