Money is the very crux of adware and spyware. These pose several problems and are a security risk.
Adware is a program that displays advertisements on the computer whether you want them or not. They are not just connected to particular websites or free software but are programmed to start up whenever your computer is switched on.
Programs like Eudora mail client display advertisements in lieu of charging registration fees for use of software. It helps developers recover program development costs. Kazaa the file sharing application comes bundled with at least three ad-ware programs. Two of them serve ads to the desktop while another redirects the users browser to a search engine with advertiser sponsored web results. Well known ones are: BroadcastPC; Comet Cursor; GeoWhere; Network Essentials, 123 Messenger, Direct Revenue, and so on.
Unfortunately, other guises of adware are spyware and malware.
Spyware is a program code that relays information about you and your work without your permission or knowledge. Some just spy on you conveying your Internet habits to marketing companies, while others are thieves they access credit card information as...