Why does Spyware and Adware affect every internet user?

• All information you enter via the web can be intercepted
  
  
• Unauthorized sites can add themselves to your desktop (icons)
  
  
• Unauthorized sites can add themselves to your internet favorites
  
  
• Your browsing activity can be tracked and monitored
  
  
• Unwanted toolbars and searchbars can attach themselves to your browser without your knowledge or approval
  
  
• Your personal information can be sold to other parties without your knowledge or consent
  
  
• Your default homepage and settings can be hijacked so you can't
  change them
  
  
• These malicious components not only invade your PC so they can not be removed, but take up your hard drive space and slow down your PC!