Card Trick #3: Aces Together

For this trick, the aces end up on top of 4 piles of cards, even after multiple shuffles and deals.
Keep the four aces on top of the deck, and do some false riffle shuffles.
Hand the deck to your friend, and ask him to deal (face down) and to stop any time he likes.
Now ask him to pick up the cards and deal them into four piles.
Once done, ask him to turn over the top cards of each file. Aces all.