Perhaps if the WLAN module was not disabled they could have used the mac addresses of the WLAN router. But that's a good question.

Indeed, sure some might have shared personal info etc, and this case shows that the English guy recently arrested because of a cheese image was a lie, but finding the real user behind the device must have taken a lot of work, the authorities seem hesitant to share this info. Each one had also to pay a subscription and make a payment, perhaps this helped a great deal.

Jokes on you, my WLAN MAC is B00B1E55:B00B1E55:B00B1E55:B00B1E55 and yours should be too.

This doesn't help a lot if you have a neighbor WLAN in reach. They would just used that one to locate you.