Many people consider themselves to be very secure when they are surfing the internet and that very well may be true. However, there are some things that are often forgotten about. The one thing is the cookie. This is not speaking about the edible version with chocolate chips, but instead the file that a good many web sites across the internet that put onto your system that tell the site that you have visited before and what you have done.
A cookie is the way that a web site can remember the user name and password of a person so they will not have to log in each time they visit the site. This is a matter of ease of operation and some people do enjoy this feature in many cases because they do not have to spend so much time typing in the information. The cookie will also tell the site the areas that you visited and the different things that you have done.
So in essence it is the method that the site will use to track its members and gain more insight into their activities. This is where a lot of people begin to have a problem with the cookie. It is important to note that in most cases the cookie is a completely harmless file that will not create any problems for you. However, this is not always the case. There is always the chance that the cookie that a site threw onto your system could be used to track all of the activity on the computer for the purpose of less than moral activities.
Many times the information will be used for the purpose of sending spam mail based on the information that you look at. This is sometimes referred to as a “Tracking Cookie� and is something that will be picked up by a lot of the spyware removal programs that are currently in use. Cookies are also not so good for those that share a computer. Since the cookie will save the user name and many times the password for a site, this would enable others that log on to the computer to view the personal and private information on the sites that you have listed. This is very dangerous when you consider the threat of identity theft and also the fact that many of these sites may contain information on your finances as well.

Introduction Series Part 3: User Name and Password Protection
Add And Edit Cookies Firefox Extension
Delete Flash Cookies