In decent decades we've seen things like tattoos, gay marriage, and pro sports openly embracing gambling move from social taboos in the US to accepted by the mainstream. What things that are taboo today will become mainstream in the next 20 years?
I will open by saying prostitution will go mainstream in the next 20 years. Currently it is only legal in parts of Nevada. I think within 20 years, it becomes legal almost everywhere in the US.