X is not a person, it is a website run by Elon Musk.
Elon, through his company, publishes the photos. I don't think it matters whether he posted them or not. He was aware of and encouraging of the practice, at least when applied to photos of adults.
Legally, he does not. The poster publishes them onto their own page.
Legally, he does not. The poster publishes them onto their own page.