When you need to play illegitimate backups on a hacked Nintendo Switch, one of the most important tools you'll need are sigpatches; normally, custom firmware Atmosphere does not allow the running of pirated games, but these sigpatches allow users to install .NSP files that they've downloaded from the internet. As of today, though, one of the most notable and popular sources of sigpatches--user iTotalJustice's GitHub repository of them--has been removed permanently, through a DMCA takedown. The GitHub was still active as of earlier today, but if you try to access it now, you'll be redirected to a DMCA takedown form, filed by Nintendo of America.
Nintendo of America: The Nintendo Switch console and digital video games contain technological protection measures (“Technological Measures”) that permit the Nintendo Switch console to interact only with legitimate Nintendo digital video game files. This process protects Nintendo’s copyright-protected video games, including but not limited to those covered by U.S. Copyright Registration numbers PA0002213509 (Super Mario Maker 2); PA0002233840 (Animal Crossing: New Horizons); PA0002213908 (Luigi’s Mansion 3); and PA0002028142 (The Legend of Zelda: Breath of the Wild) by preventing users from playing pirated copies of Nintendo’s video games on the Nintendo Switch console.