I know theres a couple of folks with 3d printers who might have registered. (Though you dont need to register to download models you do for a few other things)
3dprintingindustry.com
Confirmed: personal data of 228,000 subscribers leaked in Thingiverse breach - 3D Printing Industry
Thingiverse has suffered a data breach in which the personal details of 228,000 subscribers have been made publicly available online.
3dprintingindustry.com