A privacy watchdog has uncovered a government memo that encourages federal agents to befriend people on a variety of social networks, to take advantage of their readiness to share — and to spy on them. In response to a Freedom of Information request, the government released a handful of documents, including a May 2008 memo [...]

The world’s rivers, the single largest renewable water resource for humans and a crucible of aquatic biodiversity, are in a crisis of ominous proportions, according to a new global analysis. The report, published Sept. 30 in the journal Nature, is the first to simultaneously account for the effects of such things as pollution, dam building, [...]