For example, if you are going to copy a domain name that is clearly a brand name and not a keyword based domain name it is not ethical to market competing products and services when you are getting traffic to your site from people typing in the brand name and then finding your site where they opt in. Some people who have brand name sites can not afford to take the legal route in suing. That is why we need a hall of shame on this site also to bring them into line.
the golden rule: Do unto others as you would have them do unto you should be foremost as you move forward with your marketing plans. There are a lot of young people with no morals involved with internet marketing. They all grew up in schools which taught them the theory of evolution as if it was fact. No wonder they have no morals.
Perhaps we should also have a hall of shame within the ethics section on this forum where we can post the web sites of violaters. That way those who can not afford the legal route will have a way to bring violaters to their knees in repentance.