What is spyware?

Generally speaking, spyware is software that gathers information about a person without his or her knowledge or conscious permission. Some of it can be fairly harmless, just tracking your activities in order to display relevant advertising (aka adware), but other types of spyware can take a great deal of control over your system - setting your start page to a particular site and forcing your browser to load specific pages during your surfing sessions. It can also be used as a conduit for installing other programs, such as keyloggers that record your keystrokes, history, passwords, and other confidential and private information.

Spyware Statistics:

15% are a severe threat - keyloggers and other applications that send sensitive information such as passwords to the spyware controller.

25% are a moderate threat - sends information such as host name, processes running on the computer, internal IP addresses, versions of software on target machine.

60% are a minor threat - sends information of commercial value such as browsing habits; keywords used for searching.

81% of home PCs lacked either up-to-date AV software, spyware protection or a firewall 

69% of computers in homes with children under age 18 had spyware/adware