The adoption was legal, and I suppose, in the world of the film, how they raised him was their business, so long as he was obviously fed and boarded and not abused in a physical sense, though even there, I have questions. But, even with the needs of a movie, and in-universe, the popularity of a TV show, at some point, I have to believe, such extreme actions taken to keep a now-grown man ignorant of the truth of his world almost have to break laws that transcend this fictional world. I can see law enforcement going lax in the face of pressure from various sources, but that wouldn't change the fact that laws were broken. I'm not a lawyer, so I don't know for certain that any big, red-flag ones were. Any help?