  We study damage spreading among the opinions of a system of agents, subjected
to the dynamics of the Krause-Hegselmann consensus model. The damage consists
in a sharp change of the opinion of one or more agents in the initial random
opinion configuration, supposedly due to some external factors and/or events.
This may help to understand for instance under which conditions special
shocking events or targeted propaganda are able to influence the results of
elections. For agents lying on the nodes of a Barabasi-Albert network, there is
a damage spreading transition at a low value epsilon_d of the confidence bound
parameter. Interestingly, we find as well that there is some critical value
epsilon_s above which the initial perturbation manages to propagate to all
other agents.
