Cookies may be delectable morsels, but the Web variety is sometimes a little hard to digest. The concept is relatively simple. When a Web site you visit dishes up a cookie, it sends a small piece of data to your hard drive. You probably won't even know when this happens. The cookie "brands" your PC with a permanent profile that the site can use to identify you if you visit again.
Online advertising agencies such as DoubleClick and Focalink send out cookies along with banner ads to help track how many times a user sees a specific ad. Agencies can also determine the path you took to get to their ad site. They use that information to see what your interests are and then match them to specific ads.
Cookies might sound creepy, but remember-they can't read your hard drive or record anything you don't volunteer. Still, many users are uncomfortable with the thought of a site depositing anything on their hard disk. To help address concerns about privacy, a cookie standards proposal (RFC 2109) headed up by Lucent Technologies' David Kristol has been submitted to the Internet Engineering Task Force for review. The proposed plan (http://portal.research.bell-labs.com/~dmk/cookie.html) would make the presence of cookies more obvious to users.
In the meantime, you can set your browser to warn you before accepting a cookie. With Internet Explorer, select View/Options and check the box labeled "Warn before accepting 'cookies'" on the Advanced tab. In Navigator, select Options/Network Preferences/Protocols and check the box labeled "Show an alert before accepting a cookie." Navigator 4.0 includes advanced filtering, which lets you automatically reject all cookies. For a list of cookies on your system, open cookies.txt in the Navigator directory or scan IE's Cookies directory in the Windows directory.
You can also visit http://www.wizvax.net/kevinmca/ for demo downloads of the NSClean and IEClean cookie monitoring tools. In addition, Pretty Good Privacy (http://www.pgp.com) offers a cookie filtering app called PGPcookie.cutter for Windows NT 4.0.