I would imagine that in most cases it would violate the service's ToS/rules. Content like this is clearly abhorrent to most people, and would quite easily fall

I would imagine that in most cases it would violate the service's ToS/rules. Content like this is clearly abhorrent to most people, and would quite easily fall foul of the boundaries set around "offensive" content on most platform. There could also potentially be legal issues in this specific case, like you say.