The things that we should know are increased by the growth of the information-oriented society. If you had little knowledge, you couldn't only put it to practical use, but sometimes you'd have danger. You don't need to fear the use of computer networks; Internet, CompuServe and so on. It's so comfortable that you can get much information by use with right knowledge. The reason that I start to write this essay is that I heard about my friend's behavior. He sent his friend to private data by E-mail. I taught him that network administrators can watch any E-mail. He was surprised at this truth. At this time, I realize that ignorance of information is too danger. And I advise you to study about computer networks.
 Firstly, that E-mail is used like a normal letter is too danger. According to the standard textbook for Network Specialist, network administrators have some duty that is operation keeping, obstacle overcoming, safety checking, efficiency testing, account management, secret saving, and so on. Secret is saved by network administrators who is human. They should have moral, but you have not to forget that you save your private information yourself. If all network administrators were to have a perfect moral, your private information would not saved by any danger. Because all E-mail checking have possibility to be done if troubles are happened in your company, school, etc. Nevertheless with this knowledge, no one use E-mail like a normal letter. Knowledge like this is so important to use E-mail.
 Secondly, your personal information shouldn't be sent to any area by yourself. Because you can't know where your data is used. Japan Times reported, ""The fears about credit card numbers on the Net haven't moved me that much since I give my credit card to people in restaurants all the time and they take it out of my sight where I can't see what they're doing with it," said David Hantunen of Daly City, Calif." This idea is right. It's the same on computer networks and real communication, but many people forget the truth. Dancing on the media that saying information-oriented society is forgotten this tiny fact from your mind. This same among the different media should be reinput to every computer network users heart. It's a easy problem, but many people have forgot, and now I tell you that you haven't to send your private information to any place.
 Third problem is that an expression over computer networks is so free that we should have a responsibility of the information that we don't only send, but receive. Because the legislation prohibiting the distribution of incident material to minors over computer networks was issued a restraining order at the Federal Supreme Court in United States at Jun. 26 1997, we are called to account about use of computer networks. "The Judice Department argued in a brief filed on Wednesday that the act is clearly worded to apply only to "patently offensive" material and aimed only to keep it [Internet indecency] inaccessible by children." reported at Feb. 17 1996, on Japan Times. As a consequence of judging the law as violation of the constitution, you compulsory have to save children from Internet indecency. You think that when you receive an information from computer networks, realizing this truth is equal not to realizing, don't you? On the contrary, that you don't know this fact is considered as a danger. And you should know that you always promise your and others' expression when you send and receive a computer networks' information.
 Knowledge is needed for using computer networks. These problems that is picked up are dangerous for you, and I think that you have an afraid a little. You don't have to have a fear to use computer networks. You shouldn't accept an idea, that is tolled on many computer magazines is computer networks using are carefree, without your cool thinking. And It's good that you have a chance to hear thinking from administrators and other specialists for having knowledge of information. You have to fit to the information-oriented society that is so comfortable with right knowledge of information and cool thinking that is the same on real communication.

Works sited
1. Amari,Naoyuki. Standard Textbook for Network Specialist. Ohm-sha, 1995 : 169-172.
2. Katou,Sho. Short Span Counterplan Book for the 1st Type Examination of Informarion Technology. Gijyutsuhyoron-sha, 1996. : 85-104. and 237-54.
3. Kitajima,Jyuji. Unconstitutional Judgement to Regulate to Pornography on Line. Asahi-shinbun, 28 Jun. 1997. : 29.
4. Japan Times. Big News the First Half Year of 1996 on Japan Times. Japan Times, 1996. : 40-43. and 142-45.