Lemme give you an example. The most recent cases in Canada on the issue of same-sex marriage were decided on what I would term faulty evidence; that is, the evidence that decided the case was largely anthropological and cited examples of same-sex marriage type relationships in various cultures in the world. The vast majority of the evidence submitted on these groups was incredibly one-sided. How do I know? I researched one of these groups extensively, and the same-sex marriage situation in this scenario arose out of necessity i.e. no male descendants in the family to pass property on to. In this particular case, the eldest daughter would marry a woman of the tribe, and her kinsmen would copulate with her "wife" to raise offspring in the father's name. This was just one example, but the vast majority of these types of relationships amounted to nothing more than legalised prostitution. Nevertheless, the flawed research cited by the pro- same-sex marriage groups was the only evidence presented, and played a substantial role in the striking down of the common law definition of marriage in British Columbia and Ontario.