Not sure how that even applies here. The books arrived in sealed boxes and remained in the guy's home, free from public view. Nobody should even know that the guy has the books, making it even more powerful than "you do not have a right not to be offended". You do not have a right to open other people's mail and be offended, because you do not have the right to open other people's mail!
If I read correctly, the package was opened by customs officials. While slightly annoying, it is their job to open packages from time to time, and it has its uses.
The problem is it should not fall on me to keep my manga hidden. It's actually pretty hard to keep something completely out of sight... should he make a special room locked at all times just because he _may_ have questionable materials? I'd say "you don't have the right to be offended" is the more general principle here, and solves the issue much more elegantly then privacy.
Not sure how that even applies here. The books arrived in sealed boxes and remained in the guy's home, free from public view. Nobody should even know that the guy has the books, making it even more powerful than "you do not have a right not to be offended". You do not have a right to open other people's mail and be offended, because you do not have the right to open other people's mail!