If you own the original physical disc, downloading a WBFS is generally considered a "backup." However, courts have ruled that breaking encryption (circumventing the Wii's disc protection) is a violation of the DMCA's anti-circumvention provisions.
The Internet Archive (archive.org) is a non-profit digital library. While famous for the "Wayback Machine" (saving web pages), it hosts a massive collection of software, ROMs, and ISOs. wii wbfs internet archive
So you’ve found a game on the Internet Archive— Mario Kart Wii (WBFS) weighing in at 1.2GB. What now? If you own the original physical disc, downloading