Ethical SEO" applies to SEO techniques, not to individual SEO practitioners. SEO practitioners may behave ethically (or what they believe is ethical) towards their clients. This does not mean that their practices are ethical or in anyone's ultimate interests but their own. A range of strategies and tactics are available in order to perform search engine optimization.
The most ethical SEO technique can be defied as the one that produces the most good and does the least harm; respects the rights and dignity of all stakeholders and treats all stakeholders fairly; promotes the common good; helps all participate more fully in the goods we share as a community and a society; as well as enables the deepening or development of those virtues or character traits that we value as individuals, professions and members of a society.
The black hats write software, able to generate tons of grammatically correct but meaningless information full of keywords bringing in a lot of traffic. Two of the most common black hat tricks are spamdexing and cloaking. Spamdexing can again be separated into content spam, linking spam and others. Cloaking on the other hand, is more to mislead a search engine regarding the content of the webpage.
These techniques usually include one or more of the following characteristics:
• breaks search engine rules and regulations
• creates a poor user experience directly because of the black hat SEO techniques utilized on the Web site
• unethically presents content in a different visual or non-visual way to search engine spiders and search engine users.