3 of my last 5 Posts are exactly about this Issue.
Give them a read if you like.
They are an appeal to the whole Steemit community to stand together against the abuse of this great site by posting such content.
My first post about this was even downvoted by the very person who posted the nude pictures.
There was even one guy who took pictures of women on the street or subway to post them here, which is actually illegal, because they turn him on.
This is an offense to all women out there, to my Mother, to my sister, and all my female relatives, friends, colleagues, etc....
My appeal is simply this:
Everytime that you see a post like this, especially when it is not marked NSFW, use the Flag to downvote it.
If we can get enough Steemers together to do this they will have no chance!
At least in your settings you can filter out NSFW content.
But when they post stuff like this WITHOUT marking it NSFW, everytime you see it, please dont scroll away until you flag it.
This completely destroys any incentive for them of posting this.