The Japanese constitution has several clauses that have the phrase "for the public welfare" in them. Basically what it says is that the fundamental human rights are respected if (and only if) they do not conflict with the "public welfare".
I have been long thinking that this "public welfare" is too vague so that it can be used to condemn almost anything, because there is actually no definition in the constitution. The vagueness may not be a problem if the people are culturally, religiously, morally and biologically "uniform", but obviously it is not the case. In an extreme case, if say 99% of people think that something is ugly, then that thing can be criminalized in order to promote the public welfare (people actually claim that things they hate must be criminalized and they often cite public welfare, although making something really criminalized is rarely done in my understanding).
It turned out that, this vagueness has actually been pointed out by the United Nations as well. The International Covenant on Civil and Political Rights of the United Nations had a 'concern that the concept of "public welfare" is vague and open-ended' (page 8 of http://tbinternet.ohchr.org/_layouts/treatybodyexternal/Download.aspx?symbolno=CCPR/C/JPN/CO/6&Lang=En ). There is a very good read (in Japanese) written by a professor of Osaka Sangyo University.
I guess there are two issues about this. First, people really do not care about it because for the majority of people who share the same way of thinking, something against the public welfare is what they do not want. So, condemning something against the public welfare is actually good for them! It might be the case that people do not even notice that the phrase "public welfare" is vague. Second, having a constructive and objective discussion on how to change the constitution is very difficult in Japan, because people are paranoid about the Clause No. 9 that says about the wars and forces (and I am too).