Purchasing train tickets with cash, exiting a train before or after other passengers, or appearing calm or nervous are all examples of behavior that Amtrak employees have been told to report as "suspicious activity."

A document entitled Guidelines for Amtrak Customer Service Employees, which was obtained by the ACLU after an FOIA request, lists a number of different behaviors that are "indicative of criminal activity" and should immediately be reported to law enforcement personnel by Amtrak ticket agents.

Those behaviors include;

- Unusual nervousness of traveler
– Unusual calmness or straight ahead stare
– Looking around while making telephone call(s)
– Position among passengers disembarking (ahead of, or lagging behind passengers)
– Carrying little or no luggage
– Purchase of tickets in cash
– Purchase tickets immediately prior to boarding

Of course, such behaviors are so ludicrously broad that virtually anyone is likely to have engaged in at least one of the above activities at some point for a perfectly innocent reason. The demonization of using cash as a tool of criminals or terrorists is also a theme that has become more prevalent in recent years, primarily because authorities dislike the anonymity of hard currency.