This is an overview of some of the ethical controversies associated with randomization. It includes an interesting story of an early trial by Archie Cochrane that raised a lot of fuss at the time because it was attacking one of the “sacred cows” of medicine.
Harford T. The random risks of randomised trials. Financial Times. http://www.ft.com/intl/cms/s/2/59bb202c-ca7b-11e3-8a31-00144feabdc0.html#axzz30BOFBYb7. Accessed April 28, 2014.