iPhone thief's identity revealed by Apple GDPR tool
reincubate.com
reincubate.com
That person might have purchased it or otherwise received it, without being aware of it's origin. Lots of people buy secondhand/refurbished iPhones, and not all of the sellers are reputable, yet people still buy.
Oh well. At least the article's author can prove that the phone was once his, and he might be able to find where it is now, and maybe even get it back, however devalued it is by now.