We have chosen to keep our FasTrak transponders in anti-stat bags to prevent our movements being monitored beyond any toll crossing for which they are needed. It’s no big deal to pull them out of the console and throw them upon the dash when we have to cross a toll bridge. Our son says he doesn’t ever use his and because they use license plate readers at toll locations, he claims they aren’t really necessary. And although it’s against the law, we don’t run front license plates on any of our cars. We’ve done that for years and never had a problem with the cops for so doing.
Ever test the ant-stat bag by leaving the FasTrack in it when you place it on the dash at as you roll thru a toll gate.? If it works your Fastrak account shouldn't be debited normally but they will correlate your car to you via a plate reader. and you will get debited and you should see how they did it proving the bag actually works or not.
The reason I say this is because in some areas (NYC) the transponders are used for more than ease of toll payment.
https://www.youtube.com/watch?time_continue=25&v=JCwWVxGtYgE