Parallelwelten (parallel worlds) are worlds invisible to anyone not part of them. More and more, our reality is defined through digital products, which afford us infinitely more freedom than in the analogue past. But increased choice has also heightened our susceptibility to manipulation. Filter bubbles, fake news and alternative facts are just data that can be easily and cheaply manipulated. We now live in multiple realities that are increasingly losing touch with each other. Reality has been turned into bits. Or is it the other way around? The digital world increasingly defines, controls and governs the analogue world. Tech companies buy and sell the raw data of human experience. Our human behaviour is turned into data, which is processed into information and then manipulated and fed back into our information diet to control our behaviour. Data is the raw material, and information - not content - is king. Information even defines reality. This book investigates these parallel worlds from different angles: technological, corporate, scientific, cultural, economic and political. It doesn't view tech as an end in itself and something the rest of the world simply must adapt to. Instead, it asks how tech can solve real problems and make the world not a worse place, but a better one.