"Normal" is a statistical attribute of any given set whether this set is a group of people or bunch of marbles in a bag. What is "acceptable" is defined by laws. What is "normal" is not necessarily "acceptable" and vice versa.

For example if 75% of inmates in a certain prison use drugs, this makes using drugs in that prison a "normal behavior", but it is not definitely an "acceptable behavior".

In personal matters, laws don't and shouldn't dictate what is the normal behavior of a society upon every individual. Although an individual might have a certain personal habit that is not within the norms of the society, laws especially should protect that individual instead of forcing him/her to behave according to the norms.

Discriminations begin when people mix up "acceptable" with "normal" due to their ignorance and self-satisfaction. I hope that helps.