Electric vehicle charging cables gets locked into the vehicle with the doors, so no one can simply unplug the charger and run with it unless the doors are open. The user will also receive a notification, as soon as their charger is unplugged.
We haven't had a case of stolen cables so far.
In addition to that, you have the option to install a protective cover (~$15) over the outlets that allows people to put a pad lock on the connected cable as shown in the image bellow.
I would suggest starting with no pad lock (for ease of access) and allowing the option only if necessary.
Fun fact: Some mobile EV chargers, though unnecessary for most vehicles, can also take a pad lock.