When the original Xbox video-game console went on sale in 2001, it wasn't clear why Microsoft, known for staid workplace software, was branching out into fast-paced action games. But Microsoft decided that capitalizing on the popularity of gaming could help the company position itself for the coming wave of home digital entertainment.

Foursquare now provides its merchant platform to more than 300,000 businesses, which can track their customers through a newly launched analytics dashboard. Merchants can analyze various metrics over time, including how many check-ins are recorded each day, who the most recent and most frequent visitors are, how visitors who check in break down by gender, and what time of day the most people check in; businesses with multiple locations can aggregate statistics to fit their needs. Foursquare provides the same platform "for Joe's coffee shop and Starbucks," says Eric Friedman, Foursquare's director of business development, but companies use the tools and data in different ways, depending on their specific objectives. "Some people are using it directly to measure [differences between] top-performing stores and low-performing stores," Friedman says. Others might track geographic differences.

What happens if Facebook or Twitter or, say, your blog hosting service, makes you take a different user name? Sound impossible? It’s happened. Last week, a software researcher named Danah Boyd woke up to find her entire blog had disappeared, and in fact, had been renamed, because her hosting service had given her blog’s name to someone else.

And as important as they are, what protects our accounts are the terms of service agreements. If you read them—and who does?—you’d learn, probably to no surprise, that they protect the provider a lot more then they protect you.

For example, by looking at the location metadata stored with pictures posted through one man's anonymous Twitter account, the researchers were able to pinpoint his likely home address. From there, by cross-referencing this location with city records, they found his name. Using that information, the researchers went on to find his place of work, his wife's name, and information about his children.

Therein lie the frustrations of Kurzweil's brand of tech punditry. On close examination, his clearest and most successful predictions often lack originality or profundity. And most of his predictions come with so many loopholes that they border on the unfalsifiable. Yet he continues to be taken seriously enough as an oracle of technology to command very impressive speaker fees at pricey conferences, to author best-selling books, and to have cofounded Singularity University, where executives and others are paying quite handsomely to learn how to plan for the not-too-distant day when those disappearing computers will make humans both obsolete and immortal.

In what labor officials and lawyers view as a ground-breaking case involving workers and social media, the National Labor Relations Board has accused a company of illegally firing an employee after she criticized her supervisor on her Facebook page.

So how important is preventing cheating? How much privacy are you willing to sacrifice in the interests of a level playing field?