The diffusion of the Internet has resulted in deep social, economic and cultural transformations. In education, there has been growing expectation of its use in daily school activities. In such a context, it is assumed to be the school teachers responsibility not only to introduce the new technologies in daily pedagogical practices but also to operate the transformations in such practices that these technologies require. Such a challenge, on its turn, seems to be a source of personal conflicts, tension and suffering for these professionals. Aiming at investigating the personal and/or professional problems they are being faced with, 20 interviews were conducted with elementary and high school teachers that use this technology with their students. Analysis of their discourse reveals that, confronted with the novelties brought about by the Net, these teachers are re-evaluating their own participation in the pedagogical process in at least three areas, which are particularly sensitive for them. (1) They are reviewing the concept of knowledge - that of transmission of established truths - which has traditionally supported pedagogical practices. (2) They are questioning the role of the teacher as the one who always knows in the information age and trying to reconstruct their professional identity in the face of a reality that subverts trsditional expectations and hierarchies. (3) They are re-evaluating the stability of their jobs because they are afraid to be replaced, or made unemployable, by machines or younger teachers who know how to operate them.