  We propose a discrete model for how opinion about a given phenomenon, about
which various groups of a population have different degrees of enthusiasm, such
as fanaticism and extreme social and political positions, including terrorism,
may spread. The model, in a certain limit, is the discrete analogue of a
deterministic continuum model suggested by others. We carry out extensive
computer simulation of the model by utilizing it on lattices with infinite- or
short-range interactions, and on (directed) Barabasi-Albert scale-free
networks. Several interesting features of the model are demonstrated, and
comparison is made with the continuum model.
