Are you aware your E-Z Pass, i-Pass, i-Zoom, etc. transponders are being scanned in more places than just toll booths?

Someone set up a device that listens to his transponder as he travel around and goes about his business. Whenever the transponder outputs its data, his box makes a beep tone. He was shocked to see how many times it went off during the day. There are readers hidden behind signs and even commercial places. Presumably this data is being collected by some agency or agencies somewhere.
He has decided to put the transponder in the shielded bag and keep it in his glove compartment until he is driving on the Thruway and wants to enjoy the convenience and small reduction of toll rates.

I saw that McD tried tying into the system so customers could have their bills added directly to the EZ pass accounts. Unfortunately there were thefts of transponders by miscreants who broke into cars so they can get their Double Big Macs with cheese for free. Meanwhile the data is being collected. What do you think they are doing with it?
Will you wrap your transponder with aluminum foil and put it away until you need it?