The market for used iPhone’s is fraught with risk, because you may end up paying hundreds of dollars for a locked off device, or worse — one that appears legit but can’t make calls. Apple has just revealed an iCloud tool to nip that in the bud by letting you check a device’s activation lock status. All you’ll need is the iPhone’s IMEI or serial number. If you’re the rightful owner, you’ll get info on how to disable any activation locks before selling.