Computer ethics is a branch of practical philosophy which deals with how computing professionals should make decisions regarding professional and social conduct. The term "computer ethics" was first coined by Walter Manermid-1970s, but only since the 1990s has it started being integrated into professional development programs in academic settings. The conceptual foundations of computer ethics are investigated by information ethics, a branch of philosophical ethics established by Luciano Floridi. Computer ethics is a very important topic in computer applications. in the
Ethics deals with placing a “value” on acts according to whether they are “good” or “bad”. Every society has its rules about whether certain acts are ethical or not. These rules have been established as a result of consensus in society and are often written into laws.
The Ten Commandments of computer ethics have been defined by the Computer Ethics Institute.
1) Thou shalt not use a computer to harm other people: If it is unethical to harm people by making a bomb, for example, it is equally bad to write a program that handles the timing of the bomb. Or, to put it more simply, if it is bad to steal and destroy other people’s books and notebooks, it is equally bad to access and destroy their files.
2) Thou shalt not interfere with other people's computer work: Computer viruses are small programs that disrupt other people’s computer work by destroying their files, taking huge amounts of computer time or memory, or by simply displaying annoying messages. Generating and consciously spreading computer viruses is unethical. 
3) Thou shalt not snoop around in other people's files: Reading other people’s e-mail messages is as bad as opening and reading their letters: This is invading their privacy. Obtaining other people’s non-public files should be judged the same way as breaking into their rooms and stealing their documents. Text documents on the Internet may be protected by encryption.
4) Thou shalt not use a computer to steal: Using a computer to break into the accounts of a company or a bank and transferring money should be judged the same way as robbery. It is illegal and there are strict laws against it.
5) Thou shalt not use a computer to bear false witness: The Internet can spread untruth as fast as it can spread truth. Putting out false "information" to the world is bad. For instance, spreading false rumors about a person or false propaganda about historical events is wrong.
6) Thou shalt not use or copy software for which you have not paid: Software is an intellectual product. In that way, it is like a book: Obtaining illegal copies of copyrighted software is as bad as photocopying a copyrighted book. There are laws against both. Information about the copyright owner can be embedded by a process called watermarking into pictures in the digital format.
7) Thou shalt not use other people's computer resources without authorization: Multiuser systems use user id’s and passwords to enforce their memory and time allocations, and to safeguard information. You should not try to bypass this authorization system. Hacking a system to break and bypass the authorization is unethical.
8) Thou shalt not appropriate other people's intellectual output: For example, the programs you write for the projects assigned in this course are your own intellectual output. Copying somebody else’s program without proper authorization is software piracy and is unethical. Intellectual property is a form of ownership, and may be protected by copyright laws.
9) Thou shalt think about the social consequences of the program you write: You have to think about computer issues in a more general social framework: Can the program you write be used in a way that is harmful to society? For example, if you are working for an animation house, and are producing animated films for children, you are responsible for their contents. Do the animations include scenes that can be harmful to children? In the United States, the Communications Decency Act was an attempt by lawmakers to ban certain types of content from Internet websites to protect young children from harmful material. That law was struck down because it violated the free speech principles in that country's constitution. The discussion, of course, is going on.
10) Thou shalt use a computer in ways that show consideration and respect: Just like public buses or banks, people using computer communications systems may find themselves in situations where there is some form of queuing and you have to wait for your turn and generally be nice to other people in the environment. The fact that you cannot see the people you are interacting with does not mean that you can be rude to them.
REFERENCE: http://www.geocities.com/lool95/computer_ethics1.htm
