Some scholars have tied toilet sex-separation to segregation based on race discrimination in the US. Advocates of this view argue that these approaches share a theme in which a warning is issued against the looming threats: violence and sexual assaults would increase. Some political activists have drawn on the commonality between public toilets being segregated formerly by race and still by sex. On the other hand, while all discrimination has commonalities, the sex-separation within racial groups, even going back to slavery, suggests that the parallel regarding toilets is historically flawed. For example, slave ships were usually separated by sex. This fact suggests that racial segregation in public toilets and sex separation in them may not be as comparable as some suggest.