Have you ever been to a site that always remembers your name, the weather for your hometown or what’s playing at the local theatre? Have you every wondered how it does that? With a normal website it is impossible to differentiate between users or visits to a website, unless the server can somehow "mark" a visitor. This is done by storing a piece of information in the visitor’s browser.  This is accomplished with cookies. Cookies are text-only files that can store database information, custom page settings, or just about anything that would make a site individual and customizable.

Why Do Sites Use Cookies?

There are many reasons a given site uses cookies. These range from the ability to personalize information (like on My Yahoo or Excite), or to help with on-line sales/services (like on Amazon Books or Microsoft), or simply for the purposes of tracking popular links or demographics (like DoubleClick). Cookies also provide programmers with a quick and convenient means of keeping site content fresh and relevant to the user’s interests. The newest servers use cookies to help with back-end interaction as well, which can improve the utility of a site by being able to securely store any personal data that the user has shared with a site.

Yes. Whether you use Netscape or Microsoft Internet Explorer (MSIE), your cookies are saved to a simple text file that you can delete as you please.

In order to do this properly, remember to close your browser first. This is because all your cookies are held in memory until you close your browser. So, if you delete the file with your browser open, it will make a new file when you close it, and your cookies will be back.

Remember that deleting your cookie file entirely will cause you to "start from scratch" with every website you usually visit. So, it may be preferable to open the cookies.txt file (in the case of Netscape) and remove only the entries you don’t like, or go to the cookies folder (in the case of MSIE) and delete the files from servers you don’t want.

Both Netscape and Microsoft Internet Explorer (MSIE) allow some level of cookie verification. Netscape 3.0 and MSIE 3.0 allow you only to "alert before accepting cookies." This is done through the Options/Network Preferences/Protocols menu (for Netscape) or the Internet Options/Advanced menu (for MSIE). This means you can read each cookie as it comes in, and hit "OK" to allow it, or "Cancel" to reject it.

Netscape 4.0 and MSIE 4.0 go one better. They have menu options that allow you to accept all, some, or none of your incoming cookies. In addition, the "warn before accepting" feature is still present in both, if you want to screen your incoming cookies.

In Netscape 4.0, go to the Edit/Preferences/Advanced menu. You will see all of the above choices. In MSIE 4.0, go to the View/Internet Options/Advanced menu. There you can accept all, warn before accepting, or reject all.

MSIE 5.0 has a lot of menu and dialog changes, but you can still disable cookies. Go to the Tools/Internet Options/Security menu. In there, you can choose the security level for 4 different browsing conditions: Internet Sites, Local Sites, "Trusted" Sites, and Restricted Sites. If you select "Internet," and click on Custom Level, you’ll get a dialog box where you can accept all, warn before accepting, or reject all cookies.

No. A cookie is a simple piece of text. It is not a program, or a plug-in. It cannot be used as a virus, and it cannot access your hard drive. Your browser (not a programmer) can save cookie values to your hard disk if it needs to, but that is the limit of the effect on your system.

Are Cookies a Threat to My Privacy?

As with everything else about the Internet, you are only as anonymous as you want to be. The sad truth is that revealing any kind of personal information opens the door for that information to be spread. The very nature of Web servers allows for the tracking of your surfing habits alone, and other information about you can be gathered with time.

While cookies themselves are not gathering that data, they are, unfortunately, used as a tracking device to help the people who are gathering that information. As information is gathered about you, it is associated with the value they keep in your cookie.

To reiterate, a cookie alone cannot read your hard drive to find out who you are, what you income is, your e-mail address or where you live. The only way that information could end up in a cookie is if you provide it to a site and that site saves it to a cookie.

Limits on Cookie Retrieval

The main limit on retrieving a cookie is that a website can only retrieve cookies that originated from that same website. That is, a script on www.myserver.com cannot read cookies from www.yourserver.com. This is mainly governed by user browsers, as browsers know the URL that they are accessing, and only transmit cookies for that server.

May people fear that accepting cookies from a website will exchange their privacy and personal information in exchange for a little added convenience or personalization when going to their favorite sites. Most cookies are harmless and many websites you visit might not even function without a way of recognizing who you are. If you are concerned about advertising cookies you should periodically review the stored cookies on your computer and examine any you don’t recognize.