  The Internet is a complex system, whose temporal behavior is highly
nonstationary and exhibits sudden drastic changes regarded as main shocks or
catastrophes. Here, analyzing a set of time series data of round-trip tim
measured in echo experiment with the Ping Command, the property of
"aftershocks" (i.e., catastrophes of smaller scales) after a main shock is
studied. It is found that the aftershocks obey Omori's law. Thus, the Internet
shares with earthquakes and financial market crashes a common scale-invariant
feature in the temporal patterns of aftershocks.
