We at Nanowerk do not endorse or encourage piracy at any level or in any form. While looking through 3D print websites for free 3D STL files, all the responsibility falls on you to check the copyright ...

Please ensure your 3D model meets the following printer-specific requirements: File Format— Your 3D model file must be saved in STL (binary.stl) format. Make sure to export your design in "millimeters ...

and it’s a Python library to convert images or text to 3D-printable STL files. The examples shown are quite impressive, and it even does a top notch job of taking a 2D company logo into 3D!