How effective is this type of crime system with Activation Lock-secured iPhones? You can't just wipe an iPhone from DFU mode and then set it up normally without the owner's Apple ID information.
Do they try to sell to people who they know won't check if the device has Activation Lock and then disappear when the buyer discovers it doesn't work?
I know someone who fell for this. Even though they were skeptical when they received the message, they thought there was a chance it was legit, and therefore gave them some change to recover their stolen phone. I guess they had nothing to lose, as the chance of recovering the phone was ~zero anyway.
Very common to then aggressively try to phish the user's iCloud credentials and remove the activation lock; third-party vendors offer this sort of service, and they're very convincing.
Do they try to sell to people who they know won't check if the device has Activation Lock and then disappear when the buyer discovers it doesn't work?