By Kate Murphy, New York Times Business, May 2/3, 2012

[....] Before you can thwart the snoopers, you have to know who they are. There are hackers hanging around Wi-Fi hot spots, to be sure. But security experts and privacy advocates said more worrisome were Internet service providers, search engine operators, e-mail suppliers and Web site administrators — particularly if a single entity acts in more than one capacity, like Google, Yahoo, Facebook and AOL. This means they can easily collect and cross-reference your data, that is, match your e-mails with your browsing history, as well as figure out your location and identify all the devices you use to connect to the Internet.

“The worst part is they sell this extremely creepy intrusion as a great boon to your life because they can tailor services to your needs,” said Paul Ohm, an associate professor at the University of Colorado Law School in Boulder who specializes in information privacy and computer crime. “But do most people want to give that much away? No."

He advised [....]