A rchive Date
[ 10-06-2000 ]
Category
[ Information Technologies ]
sub-Categoy
[ Networking ]
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[Cookies - Part2 - GENERAL QUESTIONS/MISCELLANEOUS
2. GENERAL QUESTIONS/MISCELLANEOUS
2.1 Introduction
This section is devoted to general questions on cookies and their usage.
2.2 Can I delete cookies?
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 web site 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.
2.3 How do I set my browser to reject cookies?
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.
Once a cookie is rejected, it is thrown out and not saved to memory or disk. Don't forget, though, that servers will keep looking for the cookie even if you have discarded it and may try to replace it as you surf around.
This fact is almost comical in nature. Essentially, without a cookie to tell the server who you are, it can't remember not to send you any cookies!
2.4 Are Cookies Dangerous to My Computer?
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.
2.5 Will cookies fill up my hard drive?
Both Netscape and Microsoft have measures in place that limit the number of cookies that will be saved on your hard drive at one time.
Netscape limits your total cookie count to 300. If you exceed this, the browser will discard your least-used cookies to make room for the new ones.
Microsoft saves cookies into the "Temporary Internet Files" folder, a system folder that you can set the maximum size of (the default is 2% of your hard drive).
In any event, remember that the average size of a cookie ranges from 50-150 bytes. You would need about 20 million cookies to fill up a 2GB drive. This is incredibly unlikely.
2.6 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 YOUR INCOME IS, 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.
The never-ending ethical debate associated with these facts shall be left to other forums. However, it is wise to consider carefully the information you collect and share over the Internet.
2.7 Sites are telling me I need to turn on cookies, but they are on. What's wrong?
There are three likely possibilities for problems like this. Firstly, the site you are visiting may be detecting cookies improperly. As a result, it may appear to the site that you are rejecting cookies when in fact you are not.
Another possibility is that you may be running software that interferes with cookie usage. There are many filtering and blocking software packages available for Internet users these days, and many of them also filter cookies. If you are running software like this, then your computer may not receive or send cookies. This will cause sites you visit to assume you are not accepting cookies.
Finally, your machine may be behind a firewall or proxy server that prevents cookie transmission. This is most likely in a corporate environment. So, regardless of how your browser is set, cookies won't be sent or received by your browser. Since the cookies aren't making it through to your browser, the Web Site will assume you personally aren't accepting them.
2.8 I deleted my cookies, and I can't log-on to my favorite site anymore. What can I do?
Many sites use a cookie to keep track of your settings on their servers, and to help you log in to their site. If you lose your cookie, that site cannot recall your settings for you to use.
If this happens to you, the best thing you can do is contact that site's webmaster or customer service department.
2.9 How did I get a cookie from doubleclick.net? I've never been there!
From section 3.3, we see that a server cannot set a cookie for a domain that it isn't a member of. However, almost every Web user has gotten a cookie from "ad.doubleclick.net" at one time or another, without ever visiting there. DoubleClick and other advertisers have employed a clever solution that enables them to track users and serve media content without violating this rule.
Most sites on the Internet do not keep their advertisements locally. Rather, they subscribe to a media service that places those ads for them. This is accomplished via a simple HTML call to the media service. When a page is requested, it is assembled through many HTTP requests by the browser. First, there is a request for the HTML itself. Then, everything the HTML needs is requested, including images, sounds, and plugins.
The call to the media service is an HTTP request for an image. Once the request is made to the media service, it can return more than just an ad. It can also return a cookie. Or, if is has given the user a cookie previously, it can read that first, and check to see what ad to send. The net result is that the user gets a cookie from the media service without ever having visited it.
This usage of cookies is the most controversial, and has led to the polarized opinions on cookies, privacy, and the Internet.
2.10 I looked at my Internet Explorer cookies, and they had my username on them! Can servers see my username?
Because Windows systems allow more than one user to login and use programs, Microsoft had to come up with a way to keep each user's cookies separate on a given machine. This can be common in workplaces, where a single machine is shared by many employees.
This is accomplished by appending the username to the cookie file name. This way, both Jane Doe and Joe Smith can get cookies from coolsite.com and they don't get over-written. Also, this stop's Jane from using Joe's cookies while she's surfing, since the browser will only use her cookies when she is logged in. That is, the cookie file: jdoe@coolsite.txt
Contains Jane Doe's cookie for coolsite.com. If anyone else logs-in, then this cookie is not used.
This is the only reason that the username is part of the cookie file name. The username does not get sent to the server with the cookie data. ]
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