In case you haven't been following the Pokemon Swordand Shield online scene; players recently discovered a glitch that allowed them to disconnect from a game at the right moment to ensure that they didn't lose rank and their opponent didn't gain rank in the process.
It's a nasty move, but Game Freak now has a solution: do it regularly, and you're banned. In an announcement by way of their official site, Game Freak acknowledges the issue, and says that it will "investigate" accounts to see if they have been "performed repeatedly." If they deem you a troublemaker, you could be temporarily or permanently banned from the game, and excludes from all future ranked battles and competitions.
Game Freak says it will "continuously" monitor the situation and keep users abreast of what's going on in the future. It's smart of them to be so bold this early on: a situation like this could have catastrophic results on the competitive Pokemon community.