Much of its success comes down to its ability to raise huge revenues from selling targeted advertising. In order to do this effectively, it relies on vast amounts of personal data.The Guardian’s UK technology editor, Alex Hern, discusses how Google’s stated mission is to organise the world’s information to make it universally accessible and useful. But in doing so has it ushered in a new age of mass surveillance? And if so, should we be worried? Also today: the Guardian’s Lois Beckett on a weekend of terror in the US cities of El Paso, Texas, and Dayton, Ohio, where at least 29 have been killed in mass shootings.