There are many examples of a law that implements an ethical principle, such as the laws of theft, murder, marriage, copyrights etc. Laws that implement ethical principles exist for the sake of societal harmony and to maintain stability among the communities. One such law is the Law of Bribery (Title 18 of the US Code). The government prohibits any form of bribe (commodities or money) given or taken. Both, the person who takes bribe and the person who is involved in initiating the bribe are answerable to the Government and are punishable.
A law that enforces a particular group's idea of how people should behave might not always be accepted by everyone. It might be a controversial law with many contrary beliefs that would come into play. An example of one such law is, that in New Jersey, "You cannot pump your own gas". In a book by Pam Hersh, "To Pump or Not to Pump" that was published in 2000, few of the reasons why this law is implemented was that, the gas prices in this state was comparatively on the lower side, and to make up for the costs by hiring and paying for the employee. Also it is claimed to create more jobs on the job markets. Inspite of the arguments that follow this law, this law is under full implementation.
Cornell Unversity Law School (online). Accessed 9/26/2012. http://www.law.cornell.edu/uscode/text/18/part-I/chapter-11 Dumb Laws (online). Accessed 9/26/2012. http://www.dumblaws.com/law/686 Baase, Sara. 2008. A Gift of Fire: Social, Legal and Ethical Issues for Computing and the Internet. 3rd ed. New Jersey: Pearson/Prentice Hall