I recently wrote an article that dealt with three evils plaguing the Internet. These were viruses, SPAM and Popups. There is a fourth and lesser known evil called spyware. Chances are very good that if you are running a version of Microsoft Windows, you also have spyware on your computer as well.

To some extent, the public is pretty well educated on viruses and it is routine for most people to buy software that protects their computers from them. The problem with viruses is that there is a huge conspiracy that keeps the whole story of spyware quiet.

Spyware is software that resides on your computer and runs in the background. It uses a channel on the Internet to send private information out to advertisers who pay for this information. Spyware can report what websites you have visited, how many times, when and it can even send out information that you put into forms. There is almost no limit to the information that spyware collects off of your computer.

I make a habit of trying to find Open Source software as Open Source is not only free but its source code is available for inspection. Downloads from such sites as download.com or other download sites might be a combination of the program you expect and an unexpected program that installs on your computer and sends out information in the background.

One example of spyware is Gator. Gator bills itself as a program that helps you remember data that that you use to fill in forms. Gator sends some of this data out to its GAIN advertising network. Gator also automatically updates itself.

Hotbar is a program that adds graphical skins to Internet Explorer. This program not only monitors your browser clicks, it also creates a channel for graphics, e-mail and adds to come into your computer.

Xupiter is a spyware package that ads a search button to your IE tool bar that uses its own advertiser supported search. It also adds a list of bookmarks to your bookmarks and even changes your home page.

Top Text from Ezula changes the links on your current web page to link back to advertisers paying to direct unsuspecting users to a particular keyword. Ezula creates a hot link to certain words on the text of a web page and underlines these with yellow. If you click on this link, you will be taken to an advertiser paying for you to be hijacked to their site.

Many of the advertisers engaging in this sort of low-life advertising are selling pornography and adult material. It is very easy for a young person to innocently be directed to a pornographic site while doing research for their homework.

Top Text has been historically linked to Kazaza as early downloads of Kazaza automatically installed Top Text.

Some spyware blocks banner ads and other legitimately sponsored advertising and replaces it with banners from advertisers paying to have their banner ads displayed instead. This is one of the biggest threats of spyware because in order for people to continue to enjoy free web content, advertisers must feel confident that their paid ads will reach the people coming to the websites the sponsor.

Some hackers have dropped spyware into legitimate programs and try to collect sensitive information such as passwords and credit card numbers by having this data sent over a channel.

Manually removing spyware is not easy. The spyware does everything it can to hide itself from the user. Many websites have published instructions how to find and remove individual spyware packages. One site that has a lot of useful information is ScumWare.

There is a very good free software package that you can download to remove most spyware from your computer. The software is called Ad-aware. Ad-aware's free package will remove existing spyware from your computer. Commercial versions of Ad-aware will prevent spyware from getting into your computer and will monitor the activities of programs on your computer to insure that no sensitive information is being sent out of your computer. Ad-aware can be downloaded from Lavasoft's web site.