How to Muddy Your Tracks on the Internet

While it’s probably impossible to cloak your online activities fully, you can take steps to do the technological equivalent of throwing on a pair of boxers and a T-shirt.

Some of these measures are quite easy and many are free. Of course, the more effort and money you expend, the more concealed you are. The trick is to find the right balance between cost, convenience and privacy. 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.