The NTSC-U ISO can be patched (via Wiimmfi Patcher) to restore online features on private servers:
If you're looking to play Super Smash Bros. Brawl, I recommend purchasing a physical copy of the game or checking if it's available on the Wii U Virtual Console or other Nintendo platforms, where you can buy and download it legally. Super Smash Bros Brawl Ntsc Iso
For those interested in playing Super Smash Bros. Brawl, several alternatives exist: The NTSC-U ISO can be patched (via Wiimmfi