There’s a story going around that Apple is maliciously disabling iPhones that weren’t serviced by an Apple authorized service organization. Here’s a good post about it on Tech Insider.
What’s happening in many of these “Error 53” cases is that Apple is sensing that a Touch ID sensor is not properly paired with the rest of the system. Since Apple can not verify the integrity of the sensor—it could’ve been replaced with a different Touch ID sensor that has access to the Secure Enclave, which would be a major security breach—it turns it off or bricks the phone. Pretty serious, and badly communicated, but understandable from a security perspective.
Here’s security researcher Filippo Valsorda:
I get why people might be frustrated if they got their iPhone repaired at an unauthorized location for the sake of convenience or savings and found that their phone was zapped. Apple needs to do a much better job of communicating things. But one of the iPhone platform’s strengths is its security, and this seems like a security measure to me, not some conspiracy by Apple to claw back incremental revenue currently going to off-brand iPhone repair shops. That won’t stop people from freaking out about it, though.