Across the pond, things work a bit differently, and the criminal justice systems are a bit lower friction for the authorities as I understand it. Not that I'm criticizing mind. The American System has not endeared itself to me as of late.
When it comes to MAC addresses, 1) there isn’t a central registry of addresses anyway so having the MAC address alone won’t help much in an investigation, 2) it can be set by the user so malicious users will fake their MAC address and 3) for privacy reasons most devices nowadays will generate unique MAC addresses for each network.
The IMEI and advertising ids are the more pressing ones though. Never underestimate the deanonymyzing power of someone else's UUID you aren't even aware you have.
Quick perusal indicates Cour d'assises is the only court with a jury analog, and it only deals with matters where the penalty would result in a >10 year sentence if I'm reading it correctly.
On the other hand, plea deals are not a thing either, so if the state decides to press charges, you're definitely going to see a judge.