They don't upload them to any torrent site. Release group upload to a Top site(s), Then they pre it (publish it if you so will) and it's released, Racers spreads it to their selective sites, some where in the chain someone leaks it to the public. If it's the release group themselves (probably not since if someone finds out, they're kicked out and forever a persona non grata), a racer or how it mostly is, someone that take payment so people can access their FTP site opens the hole to the scene.
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Thanks but I know how the scene works ( I use to be on elite Snes and PCWarez BBS in the 90's). I was talking about some switch dev who could program a XCI loader for atmos and then using Vpn's upload it to TPB. How are Nitendo going to trace a program back to someone ?