Yahoo is buying digital video advertising service BrightRoll for $640 million in the Internet company's latest attempt to boost its revenue after years filled mostly with financial futility. Samsung Electronics Co Ltd has accused Nvidia Corp of infringing several of its semiconductor-related patents and for making false claims about its products, counter-suing after Nvidia filed a lawsuit against the Korean... Consumers concerned about over-sharing on public social networks are turning to private messaging apps to share texts, photos and videos with a limited group of people.