What ethical responsibilities do Internet users ...

Legally it would apply to a websites guidelines. My opinion is that we have a responsibility to be tasteful and respect the rights of others. I heard the expression, "my rights end where yours begin." The same is true in reverse, "your rights end where mine begin." The ideal is to be thoughtful and respectful in ackknowledging what another's rights are. I feel the basic rights of a person online is to not have to read or hear content that uses profanity, and that does not contain hate, racism or bad attitudes. We should have common courtesy. In other words, people should relate in healthy ways. But many in society don't care about anyone but themselves. Many are very unhealthy emotionally and have no respect for anyone. So it's not easy to implement this kind of thing. I see posts on youtube that use the F word all the time and are slanderous and judgmental of others. I feel it's wrong to assume everyone speaks in that way or finds it acceptable. Even if it's acceptable for one, doesn't mean it should be forced on another. We understand what common courtesy's are but some don't even think about using profanity or being respectful, because that isn't their way of life. They never consider that some find those things offensive. I would say that the manner we would have before a public judge, is the same way we should behave in society, including online behavior. There has been a great breakdown in society because children often don't grow up with both parents, much is missing, they don't have good training and preparation for life. Many resent what is missing in their life and release that in bad attitudes. They want someone to blame. Therefore, they can be lacking in good manners and respect for others. I think it's good to remember that it is a spiritual law that every single thing we release, will return to us in the same measure. If we're disrespectful and have no consideration for others, that is what will happen to us. If people knew what they were attracting to themselves through wrong behaviors and attitudes, I think they might rethink some of their behavior. 

If you are a writer or a blogger avoid plagiarism and avoid swearing.

The spread of the Internet also raises a number of other ethical questions about matters like privacy, the security and confidentiality of data, copyright and intellectual property law, pornography, hate sites, the dissemination of rumor and character assassination under the guise of news, and much else. Fundamentally, though, we do not view the Internet only as a source of problems; we see it as a source of benefits to the human race. But the benefits can be fully realized only if the problems are solved.