Nintendo Switch cartridge based games have a file that’s unique to each individual cartridge. The dumper and accompanying flash cart make use of that file. If Nintendo detects two people playing while connected to the internet with the “same” cartridge, there’s a high chance of them banning both consoles. So any used game anyone buys after this point runs the risk that someone dumped it, maybe an old owner who resold, maybe someone who bought and returned it, etc, which means even a legitimate user who hasn’t even heard of the flash cart could get banned. There’s also the potential issue of people using the tech in the flash cart once people figure out how to use those chips to sell bootlegged reproduction cartridges that have the same issue

Oh wow, so they've poisoned the used market for Switch games. That's disappointing.

Mmh… I suspect doing this is not legal in Europe as second hand have enforced laws.

Other laws like this (I suspect second hand Steam game licence) have been voted to protect customers from such behavior (in the mindset that customer don’t have to pay for company for having bad protection system).

We will see how Nintendo will react.

Nintendo knows the PR hit for penalizing innocent customers would be pretty bad.

If a card ID is used by only two people I would expect it to be ignored, or if a device ID is only associated with one dupe card I would expect that to be ignored.

It's the devices that use multiple dupe cards or the card IDs that are used by thousands of people that will get banned.

It will be interesting to see where they draw the line but its unlikely that they want too many false positives.

Man, games are having so many hurdles and barriers to jump just to play that I'm on the edge of giving up completely.