In most countries of the world there are legal controls governing the display and supply of pornographic images. Essentially publishers or distributors are subject to laws which seek to restrict access to adults. Quite severe penalties can be visited upon anyone found to be out of compliance.
There is a gigantic quantity of pornography on the internet and there is little doubt much of it is being published illegally i.e. it is being made available without any checks to determine whether or not the viewer has reached the requisite age limit, usually 18.
But what about pictures depicting “simple” nudity i.e. showing naked people but without there being any sexual component? Such images are not illegal in many places, although they are in some.
Lots of us who are not prudes or at all prissy recognise that attitudes towards nudity can nevertheless, quite legitimately, span a great range of perspectives among persons of many different cultural backgrounds. There is no single or “correct” view. There is therefore generally a widespread expectation that displays of nudity will be restricted to appropriate environments. Rarely will these encompass public spaces.
Even in the most liberal and liberated countries nudist beaches are generally in a secluded spot or the nudist part of the beach is clearly demarcated. This is founded on a respect for people’s right to deal with personal matters of this nature in their own way.
When it comes to the internet nudity presents special problems. It would be impossible for software to pick out an image containing a lot of human flesh and then also be able reliably to determine if there was a sexual component to it which would convert common or garden nudity to pornography. Moreover, on large platforms there simply aren’t enough human eyes available to see everything that gets posted. For this reason most of the internet companies I know of that operate in the mass market simply ban all forms of nude displays or displays of sexual organs on their site. This is a sensible, precautionary step to protect sensitivities in relation both to nudity and pornography
If people really want to publish pictures of themselves with no clothes on or to look at pictures of other people in the buff there are thousands of sites where it is perfectly possible for them to do that. But for the larger sites a ban on all forms of nudity is probably the only practical approach.