  We prove the efficiency of a new method for the detection of crucial events
that might have useful applications to the war against terrorism. This has to
do with the search for rare but significant events, a theme of research that
has been made of extreme importance by the tragedy of September 11. This method
is applied here to defining the statistics of seismic main-shocks, as done in
cond-mat/0212529. The emphasis here is on the conceptual issues behind the
results obtained in cond-mat/0212529 than on geophysics. This discussion
suggests that the method has a wider range of validity. We support this general
discussion with a dynamic model originally proposed in cond-mat/0107597 for
purposes different from geophysical applications. However, it is a case where
the crucial events to detect are under our control, thereby making it possible
for us to check the accuracy of the method of detection of invisible and
crucial events that we propose here for a general purpose, including the war
against terrorism. For this model an analytical treatment has been recently
found [cond-mat/0209038], supporting the claims that we make in this paper for
the accuracy of the method of detection. For the reader's convenience, the
results on the seismic fluctuations are suitably reviewed, and discussed in the
light of the more general perspective of this paper. We also review the model
for seismic fluctuations, proposed in the earlier work of cond-mat/0212529.
This model shares with the model of cond-mat/0107597 the property that the
crucial events are imbedded in a sea of secondary events, but it allows us to
reveal with accuracy the statistics of the crucial events for different
mathematical reasons.
