The fast-changing industry is breeding startups, which are remaking existing models and platforms to lure more and more venture capital.

Naturally, the volume of personal information has privacy activists concerned about opaque companies and governments potentially abusing their power. Just a year ago in Egypt, then-President Hosni Mubarak shut down Internet access before his government began a crackdown on political protesters.

Lest you think the issue is confined to nondemocratic governments run by despots, protests erupted in January over anti-piracy legislation in the U.S. Congress.

Buying, Selling Your Personal Data

As individual consumers navigate the digital world, the advertising and marketing industry is busy maximizing the growing volume of online metrics and analysis.

Of course the exchange and use of customer user data have been around for decades. What’s changed is the depth of data gathered, and how far and quickly that information is being sold and shared among businesses.

“People have less understanding of what’s going on and how their information is being shared,” says Rebecca MacKinnon, an expert on global Internet policy.

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