Is it fine to ask who are the search committee? I saw that some friends know who are the search committee members before their interviews. So would it be fine to ask the department who are they? And if it was fine, why the department didn't mention their names since the beginning? Could asking about their names be taken as negative thing?! A strong applicant could say that she doesn't care who are finalizing the list or interviewing her.
In general, I would recommend against asking who the search committee is. It might give the impression that you are trying to "game the system" rather than simply put your best foot forward for everyone. That said, I don't think this is a serious faux pas.

Some departments, including my own, post a list of committee assignments on their department homepages -- mostly out of convenience for their own faculty. So you might be able to answer your question without asking.