Nintendo has banned multiple users’ Switch 2 consoles from its online servers after detecting a suspicious cryptographic signature. The users had been using the Mig Flash cartridge, which allows players to run original Switch games on their console without modifying it. Despite the device’s claims that it only supports and guarantees gaming with one’s own game backups, Nintendo has now flagged hundreds of accounts linked to the device as potentially pirating games.
The ban affects users who had obtained legitimate copies of Switch games and used the Mig Flash to create backup copies of these titles on their personal console. However, the fact that Nintendo can detect this signature suggests a potential vulnerability in the device’s security measures or its ability to distinguish between authorized backups and pirated game sharing. As a result, popular hacking news account Switch Tools is now advising users not to use the Mig Flash cartridge due to its increasing risk of causing online bans.
Source: https://arstechnica.com/gaming/2025/06/playing-personal-game-backups-could-get-your-switch-2-banned-by-nintendo