MAC spoofing is considered legal - But why IMEI/MEID spoofing isn't?

I see many people spoofing MAC address for personal use.

But when I search for spoofing IMEI/MEID of a device there are so many people screaming that I should not do it whatever the reason is. What exactly is different between the two in terms of law? I think they both should be treated as the same as they tamper with the unique identity of a device.