Randomness, does it exist?

Does true randomness exist?
I mean, a random number generator on the computer uses some algorithm, it's not truely random.

Since every single event happening in the universe is simply a reaction to another event, everything can theoretically be predicted.

Example, somebody throw dices against a wall. If one calculated the exact angle and strength at which the dices were thrown, one could predict the outcome of the dices. The same goes for cards shuffling: if somebody recorded the exact motions of your hands during the shuffling, he could probably tell you the order of the cards.

No event is truly random because every event can theoretically be predicted.