Cookies have caused a great deal of debate. The following are some
of the issues:
Some users don't like the idea that a Web server can write to
their hard disk, however innocuously. In fact, there is no (real)
danger in accepting cookies - for example, cookies cannot spread
viruses.
Users worry that cookies might be used to send secret
information about them to a server. In fact, the cookie which is
returned is exactly the same as that which was sent.
Users are concerned that other Web servers might find out
information about you by reading cookies set by different servers.
In fact, browsers follow very strict rules to ensure that cookies
are only returned to the server (and/or specific CGI program) which
originally sent them.
Users worry that Web servers can track their "click-through"
behaviour using cookies. In fact, this is true, and is a potential
privacy issue.
Browsers allow the user to turn off acceptance of cookies, and
some users do this. Therefore a shopping cart application cannot
rely on the existence of cookies to maintain state
information.
Some sites with useful information on cookies include: