Twitter nudity

So many Indian users on Twitter post complete nude pictures and videos of intercourse be it straight or gay or bi or any other. Yes there is option on Twitter to label the pics as sensitive or nudity but is it that all these nudity sharing and also trade in it through only fans makes it legal? People post nude pictures, videos and then collaborate with other users to make sex videos on or not on payment basis. Also, they promote only fans and similar sites through it and attract audience for subscription basis content. How legal all of this is? What if an individual on a given day wants to do the same thing of posting nudes on Twitter and trading through onlyfans or personal, will it be legal and safe? Or is there any alternative approach to this thing?