[snuxoll]

> They'd get unscrupulous people taking phones they sold back

Money doesn't get paid until activation lock is verified as disabled. T-Mobile does this every time I trade in a phone, it's nothing new.

> or a couple who broke up where it's not clear who "owns" the phone.

There's no good way to ever handle this, ever - even without activation locks. Not worth worrying about, send the device to the registered owner and let the courts deal with it if people want to get bitchy with their former partner.