Via Forbes, a video from a Defcon conference presenter who hacked his E-ZPass and found that his car’s location was being tagged continuously while he drove through New York City:
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 [in non-toll situations] “intrusive and unsettling.”