What is Spy-Ware ?
The term "Spyware"
covers advertising systems which secretly uses your internet connection to
download banner-ads or send various user data to a third parties server - with
or without knowledge of the user.
These companies build user profiles for statistical data, or they sell it to
third parties to do target advertising.
Often an attractive "Free" host application is used to transport the
parasite.
Nearly all spyware systems hide their intentions (Gathering user specific information)
behind a nice privacy policy, shown during or before the installation of their
(customers) software.Anyway, it is like the "fine print on the back of
the ceiling". Most of the time people where not aware of the fact that
they install an advertising parasite when they installed the so called "freeware"
application.When you decide to uninstall the host application (the freeware),
the spyware will remain active on your system.
This so called "freeware" is not free at all, it may cost your privacy
or at least bandwidth and cpu resources.
Since no trojan \ virusscanner scans for them, it is not trivial to remove them
entirely or even detect them.
Some sites with info about Spyware :