It is true that when you are using the phone, your Mom can listen to your conversation from the other phone.
Same thing happens in the Internet.
When you dial into the ISP, surfing the Internet, checking E-mail, chatting with your cyberpals, your activities are subjected to monitoring and captured for later use. Most of the time we just take it for granted and assume our service provider are truthworthy. Internet Security is becoming an important part in our lives. Almost all Internet software that you use today already have the Security feature built-in. However, we seldom use these features because we don't understand how to use them.