The key fob is your lifeline to your car, letting you unlock the doors and set off the alarm, at a minimum, but how can you tell if it needs a new battery?

According to a newly-filed search warrant, Milwaukee police officers say thieves are now reprogramming key fobs to quickly steal vehicles.

Thieves can easily reprogram BMW key fobs on the spot, posing a major security risk.

I have resorted to using the ignition key to open the door, which works fine. Does a battery change necessitate a reprogramming of the fob, and if so, at what cost? — J.C., Freeport, Maine ...

The thieves used computerized devices to reprogram key fobs, allowing them to enter new cars, and they often displayed violence.

The thieves used computerized devices to reprogram key fobs, allowing them to enter new cars, and they often displayed violence.

When they arrived, they were surrounded by two to four armed men, then their vehicle reprogramming devices and key fobs were taken.