> iCloud locks or Samsung's KNOX lock entered the field because the manufacturers were pretty pissed that customers using their devices in public became a target for "enterprising" robbers who'd factory-wipe the devices and flip them to a pawn shop or second-hand store in a matter of half an hour.
It wasn't just the manufacturers who were pretty pissed at that. Minnesota passed a law requiring smartphones to have a kill switch that would allow the owner to remotely render the phone inoperable [1]. Then California did, with the California law also making kill switch support be turned on by default. Those laws have been in effect since mid 2015 and were quickly followed by a huge drop in smartphone thefts.
It wasn't just the manufacturers who were pretty pissed at that. Minnesota passed a law requiring smartphones to have a kill switch that would allow the owner to remotely render the phone inoperable [1]. Then California did, with the California law also making kill switch support be turned on by default. Those laws have been in effect since mid 2015 and were quickly followed by a huge drop in smartphone thefts.
[1] https://en.wikipedia.org/wiki/Smartphone_kill_switch