Yours & my lifetime are limited. How many controversial topics can we recall that we lived through and where they became accepted overtime? What medium was use

Yours & my lifetime are limited. How many controversial topics can we recall that we lived through and where they became accepted overtime? What medium was used at the time and was it the popular communication method for the time. I'm sure historically there was a similar fight with what mediums were available at the time. Burning books or just killing someone who speaks out. The internet can be the only method nowadays where people with little finances can make a loud enough voice be heard and there are still unpopular views I'm worried won't ever get accepted if people are not being cautious about throwing away measures. That's why the slippery slope argument is worth me typing. Even if maybe it won't!