I've never had an E-ZPass, on the basis that it made tracking my movements just too easy for the powers that be. Sometimes I've wondered if I was being overly paranoid about that.
Nope.
E-ZPasses Get Read All Over New York (Not Just At Toll Booths) (Forbes)
Puking Monkey is an electronics tinkerer, so he hacked his RFID-enabled E-ZPass to set off a light and a “moo cow” every time it was being read. Then he drove around New York. His tag got milked multiple times on the short drive from Times Square to Madison Square Garden in mid-town Manhattan and also on his way out of New York through Lincoln Tunnel, again in a place with no toll plaza.
At Defcon, where he presented his findings, Puking Monkey said he found the reading of the E-ZPass outside of where he thought it would be read when he put it in his car “intrusive and unsettling,” quoting from Sen. Chuck Schumer’s remarks about retailers tracking people who come into their stores using their cell phones.
A spokesperson for the New York Department of Transportation, Scott Gastel, says the E-Z Pass readers are on highways across the city, and on streets in Manhattan, Brooklyn and Staten Island, and have been in use for years. The city uses the data from the readers to provide real-time traffic information, as for this tool. The DoT was not forthcoming about what exactly was read from the passes or how long geolocation information from the passes was kept. Notably, the fact that E-ZPasses will be used as a tracking device outside of toll payment, is not disclosed anywhere that I could see in the terms and conditions.