The Democrat and Chronicle reports in their on-line edition that there is an email making the rounds claiming that the NY Thruway Authority uses EZ-Pass data to catch speeders. According to the D&C, the Thruway Authority, NY DOT, and NY DMV all deny that this is done.
I haven’t seen the mass email, but could it possibly be in reference to the Mean Value Theorem? If your average speed during your time on the Thruway was more than 65 mph, then at some specific time during the trip your instantaneous velocity was also over 65.
Urban legends that such data is used to issue speeding tickets have been widespread, but never conclusively proven. [Question: a speeding violation is fundamentally a driver infraction; how would the DMV know who was driving a given vehicle?]
The Thruway Authority does issue speeding violation tickets for drivers who speed through a tollway booth, and gives fines for non-EZ-pass cars that pass through an EZ-pass only lane; see their discussion of those issues for details. Whether they attempt to ascertain the identity of the driver in such cases is unclear.