What Harm Does Spyware Do?

Warnings against spyware appear all over the Internet and television, urging consumers to perform spyware searches and buy anti-virus software. Some people think these spyware warnings are overblown, but the danger to your computer--along with your personal information and financial documents--is very real. Spyware can dramatically slow down your computer and steal personal data without you ever knowing it. But that's just the beginning of the harm it can cause.

Identity Theft

Most spyware collects personal information from the computer and sends it to people who use it to steal money and make fraudulent purchases using a stolen identity. Some spyware simply breaks down a computer's protective barriers so that thieves can then hack into the computer and obtain personal information manually.

Deleting or Modifying Files and Programs

Some spyware programs go through a computer system and delete files or programs. They may delete all files or only certain types of files. A related action that spyware takes is modifying programs so that they are extremely difficult to remove from the system. Some spyware deletes important programs or anti-spyware programs that might have deleted the spyware in the future.

Sending Spam

Spam spyware collects your personal contact information or enters your email or social networking account and automatically sends out massive amounts of spam and spyware to other people's computers through email and other messaging formats.

Pop-ups

One type of spyware changes a person's homepage or alters her bookmarks and Internet settings, resulting in tons of pop-ups while a person is browsing the Web. A similar effect of spyware is the installation of numerous unwanted toolbars. Particularly bad spyware can result in pop-ups appearing in rapid succession so that a person can't click out of them, preventing normal computer use.

Slow Down Computers

One of the biggest and most obvious results of spyware is a slow computer. Some spyware programs are huge and take up a lot of space that would otherwise be used for data storage and programs. Some spyware programs also run in the background of a person's system, using operating memory so that the computer doesn't run other programs as fast as normal.