I think by now, most of the principles of SEO are more or less well understood by people that have done their time in the trenches since 1999, although new platforms and data types arrive all the time keeping the need for ongoing practice or testing even more important than in the past. The need to learn about new entrants like Siri, Alexa, Facebook, Linkedin, and specialist search engines (like Booking.com, for example) will keep SEOs on their toes for years to come.
Another ethical controversy associated with search marketing has been the issue of trademark infringement. The debate as to whether third parties should have the right to bid on their competitors' brand names has been underway for years. In 2009 Google changed their policy, which formerly prohibited these tactics, allowing 3rd parties to bid on branded terms as long as their landing page in fact provides information on the trademarked term. Though the policy has been changed this continues to be a source of heated debate. Click Here for SEO Internet Marketing