Smartphones are killing PCs. Smartphone's market vastly outperformed. PC's market in the last few years. Not only that, more that 50% of cellular phones sold today are smartphones, pushing classical mobiles into a corner. And more than 50% of Facebook connections come from a smartphone. Smartphones are a modern revolution that is changing the way we live.In this talk, we will present some of the work in systems, security,and privacy  in mobile networking that is being performed at Sapienza in our group. We will see how modern mobile operating systems are actually becoming hybrid cloud-mobile operating systems. We will see some of the new privacy and security concerns of mobile networking, and, lastly, how we can get incredibly reliable information on the socio-economic status of groups of people just looking at part of the "background radiation" coming from our smartphones.