I didn't see it mentioned in the article but I suppose the crooks use a device that they bring near their targeted vehicle, and it must somehow 'match' up with said vehicle's alarm system and open it? I can understand if a dealership has to get access to the OBD port to reprogram a key for a user that has lost their set, but making it possible to reprogram a car or key without even gaining access to it is quite reckless IMHO.
I know over here in SA, the thieves mostly use a jammer that they use to jam the locking signal from your key fob, so as you walk away from your car and instinctively lock it, they prevent the signal from reaching your car. Apparently this can be done with a normal remote gate remote or the ones that come with automatic garage doors, but I am not too sure.
The other trick they use over here is quite devious - they trail people who are alone and watch them as they load their car with groceries, and as soon as you get in your car, start it and start reversing, they toss a brick or a bottle of glass underneath one of the wheels. Most people will leave their car running, unlock the doors, and climb out and see what they ran over whilst reversing. It is then that the crooks overwhelm the person and steal the still-running car.
Sadly the hijacking industry is quite large here as they mostly get broken down for spare parts. The accident rate doesn't help this cause either