These ROMs can be downloaded for personal use. ROMs are legally available to the public.
The businesses or people responsible for the copyright are either unavailable or no longer pursuing their licensing rights. Includes content in a sort of legal 'gray area'. While you can also find ROMs in a RetroPie ROMs pack on any torrent site, you should not download any copyrighted titles as this may be illegal. It's best to research applicable legal regulations before pursuing any of these titles. Some countries allow citizens to maintain a backup copy of games or titles they already own.
In many countries, downloading these ROMs is considered a crime. ROMs are owned and licensed by existing businesses or people. The most common types of ROMs include copyrighted, abandonware, public domain, and homebrew. Not only do they vary between consoles, but they often fall into different legal territories. RetroPie ROMs come in many different file formats and varieties.