James Thaxton says he had recently thought about taking them out of his cars at night for that reason.
"It's just like having money, just sitting out," said Thaxton.
It turns out he had reason to be concerned. An E-Z Pass was stolen from one of his neighbor's cars on Pughsville Road in Suffolk last week.
According to a police report, the thief was able to get in through an unlocked door.
In Chesapeake, police say about four or five E-Z Passes have been stolen over the past two weeks.
Portsmouth police say they know of two cases: in one incident, the transponder was stolen from the mail, and in the other case it was taken from a car while it was being worked on.
According to a VDOT spokesperson, if your E-Z Pass is stolen, you need to report it to a customer service center immediately.
You're liable for any charges until it's been reported stolen.
The transponder costs $10 to replace, but that is refundable if you have a police report showing it was taken.
Thaxton says he plans to avoid becoming a victim altogether.
"I don't leave any bags in the car, I tell my wife to put her purse in the trunk every time we stop, and I guess now we've just got to start taking the E-Z Pass out as well," said Thaxton.