Again; I must iterate how wrong you are.

People can and do travel and move to different countries with their consoles. There can be multiple accounts per console. People can feasibly have two consoles right next to each other connected to different networks and swap carts between them. People can change consoles because they upgraded or because they have multiple consoles in the household. And people can and do resell carts all the time.

These situations do not matter as the logic for detection is very simple. Is cartrige A with serial ABC in more places than is reasonably expected of that cartridge? With physical copies that limitation is exactly 1 place, 1 system at a time. Irrespective of who it’s registered to or who owns it. Any cartridge that has been in more than one place at one time and your system cert is logged and inserted in the next upcoming ban wave / wave of system cert revocations. This revocation goes live on Nintendo’s servers. Your system will not get the Online Service kiss of death until after this happens.

Other checks such as location, account, how often it happens and such can and may happen after this check to automatically limit false positives and prevent you from being instantly banned. But their system works; and it’s consistent as to which condition triggers it; that’s when the identity of any physical or digital game title is in more places than it is licensed to be in. (Actively caught piracy).

And there is no way to differentiate those scenarios even if you can/could track each cart individually.

Except that they can, and do. See other comments around for the how and why…it’s related to Nintendo Gold Points.

There could be a record of which consoles have played which carts, but that gives you exactly zero information about how many owners the cart has had.

There absolutely is. An unmodified Switch console reports this sort of telemetry on a regular basis to Nintendo; and it’s clear that they can ban your system based on bad Title IDs; (basically fake title headers, or dumped cartridge headers used to conceal flash cartrige usage)

Switch accounts aren’t associated to consoles and physical game entitlements aren’t associated to accounts. Any account can be in any console at any time and instantly show in in multiple places and while you could account for travel times it’s a pretty pointless thing to do that, to my knowledge, Nintendo is not doing.

They don’t have to be. Just have to log that your System Certificate reported a new title. This System Certificate is used in all traffic to Nintendo as it authenticates your system to it’s network.

They literally have no way to do so. There is no tool in the toolset to distinguish a cart someone else bought at the store from your own carts you bought at the store and then moved from a Switch 1 to a Switch 2.

This is absolutely not true; it’s absolutely possible and even suspected that individual game carts themselves are signed with unique serial IDs or even full certificates or cryptographic signatures.

I think it’s more likely the previous owner did dump the cart on to a MIG Switch or similar ROM cart. While the NS1 cannot tell the difference; it can still be updated to do so.

I think it’s likely that in order to play titles online; your Switch 1 has to get the Cart Serial number from the cart and package it all up nicely and sign it neatly with the certificate from the system. So if said Nintendo Switch 1 already transferred that title out to a Switch 2, then there would be a record on file with Nintendo saying “NS1 with Serial XYZ transferred Title cart ABC with serial DEF to Switch 2 with serial GHI”. Then when you put that cart into a different Switch 2 it notices and informs Nintendo of the new title and cart serial…which then immediately picks up on the change of ownership.

That might not raise red flags if you handed the cart over to your friend next door; but it certainly might raise red flags if you air-mailed the cart over to your buddy a few countries over.

In general, I disable the ability of getting a ‘read receipt’ if at all possible. In the case of some rare platforms that don’t allow this; I also warn people that "Seeing a ‘read receipt’ indicator does not mean I was available to reply.

In general; people who hang on to this little indicator are also committing a larger social faux pas, and you should { [(yellow/red) flag] / address / handle } it accordingly based on your relationship to that person, your goals and the situation.

Whether that means ‘calling them out’ or kindly explaining what it actually means or explaining your approach to communications; the behavior of expecting something to happen on the receipt of a read receipt needs to be discouraged in my personal opinion.

This is problematic; and a perfect example why end users should not be trusting Windows 11, 12 or later, or any software that Microsoft outputs from now on.

AI CAN’T WRITE SOFTWARE, ONLY HUMANS CAN CREATE AT HIGH LEVELS NEEDED TO CREATE NEW SOFTWARE SOLUTIONS At Best, AI can tell you maybe what libraries might help you get 50% the way there; but it cannot, and should not ever be used to do all the work of a human.

I disagree wholly; but I understand what I see to be the underlying concern; which is a cat and mouse game of ‘who can generate a harder hash to fake?’ versus ‘who can sling the best fake hashes?’.

Alpha channels are critical. The ability to have images have transparency in them is much more useful than you believe it is. Many end users have a need for it, more than they know they do; so this argument really isn’t doing much for your stance supporting PNG. Similarly PNG has supported alpha channels for quite a while.