This is because it appears that Nintendo is going after hackers of the Switch and banning them from their online services. It is unclear as to how many players have been affected, but at least one hacker, Shiny Quagsire, has been banned. For those unfamiliar, Shiny Quagsire is a prominent member in the Switch homebrew scene.
— Shiny Quagsire (@ShinyQuagsire) May 21, 2018
However what’s interesting about his tweet is that the restrictions applied to him were on a Switch console that was not hacked. This suggests that Nintendo might have traced Nintendo accounts/devices that are associated with him, including the ones that weren’t hacked, indicating that they are serious about it.
It doesn’t seem that Nintendo plans on unbanning his account anytime soon, which means that all his console is good for is playing games and checking out the news. The restrictions also mean that he will no longer be able to access the eShop, online gaming, and other social related activities. However like we said, it is unclear how many hackers/modders have been affected, but maybe think twice if you were considering modding your Switch.