If you've ever received an unsolicited e-mail message, you know what I mean. It's a sad fact, but the Internet is full of organizations that abuse the trust of their subscribers. But unlike e-mail, cookies are largely hidden from the user's view, which makes them seem a little scarier. But cookies aren't the primary source for tracking users' movements on the Web. Just about every Web site tracks its visitors to some degree - with or without HTTP cookies.
Servers store information about the requests they receive in log files.
These files contain detailed information about every single request the server receives, including where the request came from, what time the visitor showed up, and what pages he or she looked at. Compared to log files, cookies only provide a tiny piece of added tracking ability. They allow developers to look at their traffic on the big-picture level and to recognize individual users instead of just machines. This isn't a good idea, since anyone who sees that cookie can easily read the password, and gain access to that site under the user's name. Passwords stored in cookies should always be encrypted.