Thousands of players from Pokemon Sun and Moon have been banned, because of altering their online save files.
These players have been banned from all online activities of Pokemon Sun and Moon. However, the banned players can still play the main game and do most things, the ban only limits the access to the online features.
Players that have been caught will not be able to access Game Sync, Rating Battles, Global Missions, and Battle Competitions.
When a banned user will attempt to access these features, they will receive an error code 090-0212. So if you received this code, sadly, you have been banned.
If you have an altered save game and have not been banned yet, you should be careful and fix your save file as soon as you can. It has been announced that future bans will come without notice.
The Pokemon Company and Game Freak, will dispose of any active account they find to be faulty, currently it is unclear, if the banned accounts will ever be reactivated again. If your account was banned wrongfully then you should forward your case to Game Freaks, there is a chance they might reactivate it.
Pokemon Sun and Moon, is the latest game to be affected by the save file edits and other types of cheating. It may have to do with the fact that Pokemon is easy to hack and cheat.
The competitive nature of the game has lead to some dishonest players to cheat, but the Pokemon company dedicates good amount of time to fight these issues.
We should expect some more bans in the future, until Pokemon Sun and Moon is free from these heckers. As for players that have acquired a hacked Pokemon from someone, don’t worry you are safe from the ban as long as you have not altered your save files.