If it's unwittingly, why would I bother with changing the IMEI? If it's wittingly, I'm already a criminal. And you're right, IMEI changing probably already is

If it's unwittingly, why would I bother with changing the IMEI? If it's wittingly, I'm already a criminal. And you're right, IMEI changing probably already is a default part of fencing a phone. The solution would be to make it a requirement that phones have tamper proof IMEIs.