The Internet used to be the great anonymizer. 1993 saw the famous New Yorker cartoon: "On the Internet, nobody knows you're a dog."

Times have changed. Now on the Internet, Google (News - Alert) knows more about you than you know about yourself. Amazon watches your behavior through your browser, logging which pages you visit, how long you stay on each page, even how long your mouse lingers over a button or link. It knows your buying history and selects ads designed to appeal to you.

A new technology called Bluetooth LE beacons aspires to do for bricks and mortar retail stores what browser monitoring does for Amazon online. The beacons dotted around a store triangulate into a smartphone app and enable the retailer to track how long you linger at each spot in the store, allowing the store to tailor specific offers to nudge you into a purchase. A new(ish) technology called addressable TV allows TV broadcasters to work like direct mail, targeting ads to particular individual set-top boxes, based on demographics like party registration and home ownership.

But a smartphone app alone has the potential to do far more egregious spying on you than this. For example, your Android (News - Alert) phone tells Google how fast it is moving. That's how Google marks traffic congestion on its maps. By the same token, Google knows whenever you are speeding, and of course everywhere you go, and how long you spend there. Your cellular provider (and the NSA) knows everybody you call or text. There's no need to marvel at how accurate LinkedIn (News - Alert) is at suggesting your acquaintances; it uploaded your address book – and theirs. The accelerometer in your phone knows when you go to bed and when you get up. It can estimate how much exercise you are getting, and diagnose some neurological disorders like Parkinson's disease. With millions of fertile minds dreaming up new apps, and as new sensors are added to phones over time, the mind-reading powers of your phone will continue to evolve.

In 1999 Scott McNealy of Sun was pilloried for saying "You have zero privacy anyway. Get over it." In retrospect it seems like sage advice. But if you (like me) are interested in a quixotic rearguard action, Phil Zimmerman's new Blackphone may be of interest.

Michael Stanford (News - Alert) has been an entrepreneur and strategist in VoIP for more than a decade. (Visit his blog at www.wirevolution.com.)